Additional Information (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
Dec. 31, 2015 |
|
| Supplemental Cash Flow Elements [Abstract] | |||||
| Income tax payments | $ 3,100 | $ 6,511 | $ 6,651 | $ 19,261 | |
| Interest payments on debt | 6,875 | 6,875 | 13,750 | 13,750 | |
| Interest payments on capital leases | 18 | $ 19 | 57 | $ 62 | |
| Negative cash book balances | $ 40,800 | $ 40,800 | $ 41,400 | ||