Derivative Instruments - Schedule of Derivative Instruments Classified as Assets (Liabilities) (Detail) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Derivative [Line Items] |
|
|
| Fair Market Value, Assets Current Portion |
$ 19,197
|
$ 24,338
|
| Fair Market Value, Assets Long-Term Portion |
30,259
|
44,014
|
| Fair Market Value, Liabilities Current Portion |
14,945
|
14,343
|
| Fair Market Value, Liabilities Long-Term Portion |
64,837
|
28,659
|
| Designated Derivative Instruments [Member] | Interest rate swaps [Member] |
|
|
| Derivative [Line Items] |
|
|
| Fair Market Value, Assets Current Portion |
0
|
0
|
| Fair Market Value, Assets Long-Term Portion |
0
|
0
|
| Fair Market Value, Liabilities Current Portion |
10,293
|
10,034
|
| Fair Market Value, Liabilities Long-Term Portion |
50,166
|
24,360
|
| Undesignated Derivative Instruments [Member] | Interest rate swaps [Member] |
|
|
| Derivative [Line Items] |
|
|
| Fair Market Value, Assets Current Portion |
0
|
0
|
| Fair Market Value, Assets Long-Term Portion |
0
|
559
|
| Fair Market Value, Liabilities Current Portion |
3,957
|
4,309
|
| Fair Market Value, Liabilities Long-Term Portion |
14,605
|
4,299
|
| Undesignated Derivative Instruments [Member] | Energy derivative [Member] |
|
|
| Derivative [Line Items] |
|
|
| Fair Market Value, Assets Current Portion |
18,457
|
20,856
|
| Fair Market Value, Assets Long-Term Portion |
30,256
|
42,827
|
| Fair Market Value, Liabilities Current Portion |
0
|
0
|
| Fair Market Value, Liabilities Long-Term Portion |
0
|
0
|
| Undesignated Derivative Instruments [Member] | Foreign currency forward contracts [Member] |
|
|
| Derivative [Line Items] |
|
|
| Fair Market Value, Assets Current Portion |
740
|
3,482
|
| Fair Market Value, Assets Long-Term Portion |
3
|
628
|
| Fair Market Value, Liabilities Current Portion |
695
|
0
|
| Fair Market Value, Liabilities Long-Term Portion |
$ 66
|
$ 0
|