Income Taxes - Reconciliation of Liability for Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	$ 58,148	$ 8,705	$ 12,523
Increases related to current year tax positions	910	17,650	1,377
Reductions as a result of a lapse of the statute of limitations	(1,414)	(2,065)	(3,624)
Balance at the end of the year	$ 5,414	$ 58,148	$ 8,705