Fair Value Measurements - Assets of Defined Benefit Pension Plans(Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
$ 725,770
|
$ 681,620
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
725,770
|
681,620
|
| End of measurement period |
689,499
|
725,770
|
| U.S. pension plans |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
421,385
|
421,385
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
421,385
|
|
| End of measurement period |
380,665
|
421,385
|
| U.S. pension plans | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
19,472
|
19,472
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
19,472
|
|
| End of measurement period |
35,816
|
19,472
|
| U.S. pension plans | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
401,913
|
401,913
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
401,913
|
|
| End of measurement period |
344,849
|
401,913
|
| U.S. pension plans | Cash and cash equivalents |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
228
|
228
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
228
|
|
| End of measurement period |
5,928
|
228
|
| U.S. pension plans | Cash and cash equivalents | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
228
|
228
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
228
|
|
| End of measurement period |
5,928
|
228
|
| U.S. pension plans | Short-term investment funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
6,168
|
6,168
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
6,168
|
|
| End of measurement period |
6,876
|
6,168
|
| U.S. pension plans | Short-term investment funds | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
6,168
|
6,168
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
6,168
|
|
| End of measurement period |
6,876
|
6,168
|
| U.S. pension plans | U.S. equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
104,073
|
104,073
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
104,073
|
|
| End of measurement period |
73,397
|
104,073
|
| U.S. pension plans | U.S. equity securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
104,073
|
104,073
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
104,073
|
|
| End of measurement period |
73,397
|
104,073
|
| U.S. pension plans | International equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
36,604
|
36,604
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
36,604
|
|
| End of measurement period |
33,109
|
36,604
|
| U.S. pension plans | International equity securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
36,604
|
36,604
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
36,604
|
|
| End of measurement period |
33,109
|
36,604
|
| U.S. pension plans | U.S. fixed income funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
256,196
|
256,196
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
256,196
|
|
| End of measurement period |
238,244
|
256,196
|
| U.S. pension plans | U.S. fixed income funds | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
19,244
|
19,244
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
19,244
|
|
| End of measurement period |
29,888
|
19,244
|
| U.S. pension plans | U.S. fixed income funds | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
236,952
|
236,952
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
236,952
|
|
| End of measurement period |
208,356
|
236,952
|
| U.S. pension plans | International fixed income funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
17,378
|
17,378
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
17,378
|
|
| End of measurement period |
12,165
|
17,378
|
| U.S. pension plans | International fixed income funds | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
0
|
0
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
0
|
|
| End of measurement period |
0
|
0
|
| U.S. pension plans | International fixed income funds | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
17,378
|
17,378
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
17,378
|
|
| End of measurement period |
12,165
|
17,378
|
| U.S. pension plans | Other |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
738
|
738
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
738
|
|
| End of measurement period |
10,946
|
738
|
| U.S. pension plans | Other | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
738
|
738
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
738
|
|
| End of measurement period |
10,946
|
738
|
| Foreign pension plans | U.K. |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
268,425
|
268,425
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
268,425
|
|
| End of measurement period |
276,294
|
268,425
|
| Foreign pension plans | U.K. | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
1,968
|
1,968
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
1,968
|
|
| End of measurement period |
2,600
|
1,968
|
| Foreign pension plans | U.K. | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
251,717
|
251,717
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
251,717
|
|
| End of measurement period |
258,067
|
251,717
|
| Foreign pension plans | U.K. | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
14,740
|
14,740
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
14,740
|
|
| End of measurement period |
15,627
|
14,740
|
| Foreign pension plans | U.K. | Cash and cash equivalents |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
1,968
|
1,968
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
1,968
|
|
| End of measurement period |
2,600
|
1,968
|
| Foreign pension plans | U.K. | Cash and cash equivalents | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
1,968
|
1,968
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
1,968
|
|
| End of measurement period |
2,600
|
1,968
|
| Foreign pension plans | U.K. | U.S. equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
29,051
|
29,051
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
29,051
|
|
| End of measurement period |
44,034
|
29,051
|
| Foreign pension plans | U.K. | U.S. equity securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
29,051
|
29,051
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
29,051
|
|
| End of measurement period |
44,034
|
29,051
|
| Foreign pension plans | U.K. | International equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
35,506
|
35,506
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
35,506
|
|
| End of measurement period |
23,789
|
35,506
|
| Foreign pension plans | U.K. | International equity securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
35,506
|
35,506
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
35,506
|
|
| End of measurement period |
23,789
|
35,506
|
| Foreign pension plans | U.K. | Money market funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
103,754
|
103,754
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
103,754
|
|
| End of measurement period |
103,399
|
103,754
|
| Foreign pension plans | U.K. | Money market funds | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
103,754
|
103,754
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
103,754
|
|
| End of measurement period |
103,399
|
103,754
|
| Foreign pension plans | U.K. | Government securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
42,672
|
42,672
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
42,672
|
|
| End of measurement period |
44,094
|
42,672
|
| Foreign pension plans | U.K. | Government securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
42,672
|
42,672
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
42,672
|
|
| End of measurement period |
44,094
|
42,672
|
| Foreign pension plans | U.K. | Corporate bonds and debt securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
11,669
|
11,669
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
11,669
|
|
| End of measurement period |
11,755
|
11,669
|
| Foreign pension plans | U.K. | Corporate bonds and debt securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
11,669
|
11,669
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
11,669
|
|
| End of measurement period |
11,755
|
11,669
|
| Foreign pension plans | U.K. | Mortgage-backed securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
782
|
782
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
782
|
|
| End of measurement period |
788
|
782
|
| Foreign pension plans | U.K. | Mortgage-backed securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
782
|
782
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
782
|
|
| End of measurement period |
788
|
782
|
| Foreign pension plans | U.K. | Alternative strategies |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
28,283
|
28,283
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
28,283
|
|
| End of measurement period |
30,208
|
28,283
|
| Foreign pension plans | U.K. | Alternative strategies | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
28,283
|
28,283
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
28,283
|
|
| End of measurement period |
30,208
|
28,283
|
| Foreign pension plans | U.K. | Real estate funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
14,740
|
14,740
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
14,740
|
|
| End of measurement period |
15,627
|
14,740
|
| Foreign pension plans | U.K. | Real estate funds | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Fair value of plan assets |
14,740
|
13,319
|
| Change in fair value of plan assets [Roll Forward] |
|
|
| Beginning of measurement period |
14,740
|
13,319
|
| Related to assets still held at the reporting date |
887
|
1,412
|
| Purchases, sales and settlements—net |
0
|
9
|
| End of measurement period |
$ 15,627
|
$ 14,740
|