Accrued and Other Current Liabilities - Cost per Hour Reserves (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Cost Per Hour Liability Reserve [Roll Forward] | ||
| Beginning Balance | $ 511 | $ 3,569 |
| Increases to reserves | 0 | 747 |
| Warranty provided or expired | (511) | (3,805) |
| Ending Balance | $ 0 | $ 511 |