Schedule II - Valuation and Qualifying Accounts (Details) - Valuation reserve for deferred tax assets - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Movement in Valuation Allowances and Reserves | |||
| Balance at Beginning of Year | $ 29,001 | $ 13,103 | $ 5,581 |
| Change | (851) | 15,898 | 7,522 |
| Balance at End of Year | $ 28,150 | $ 29,001 | $ 13,103 |