Retirement Plans-Assumptions (Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| U.S. | U.S. pension plans |
|
|
|
| Defined Benefit Plan Disclosure [Line Items] |
|
|
|
| Impact of change in mortality tables on projected benefit obligation |
|
$ (10,500)
|
|
| Discount rate used to compute benefit obligations |
|
4.40%
|
4.06%
|
| Discount rate used to compute periodic benefit cost |
|
4.06%
|
4.86%
|
| Expected long-term rates of return on plans' assets |
|
6.50%
|
6.50%
|
| U.K. | Foreign pension plans |
|
|
|
| Defined Benefit Plan Disclosure [Line Items] |
|
|
|
| Discount rate used to compute benefit obligations |
|
3.85%
|
3.90%
|
| Discount rate used to compute periodic benefit cost |
|
3.90%
|
4.30%
|
| Expected long-term rates of return on plans' assets |
|
5.60%
|
7.12%
|
| Scenario, Forecast | U.S. | U.S. pension plans |
|
|
|
| Defined Benefit Plan Disclosure [Line Items] |
|
|
|
| Expected long-term rates of return on plans' assets |
6.50%
|
|
|
| Scenario, Forecast | U.K. | Foreign pension plans |
|
|
|
| Defined Benefit Plan Disclosure [Line Items] |
|
|
|
| Expected long-term rates of return on plans' assets |
5.60%
|
|
|