Employee Benefit Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Benefit Plans [Line Items]
Total expense	$ 8,919	$ 9,765	$ 10,093
Parent Company
Employee Benefit Plans [Line Items]
Employer contribution match to employee contributions	100.00%