Income Taxes - Tax Receivable Agreement (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Tax Receivable Agreement
Cash savings percentage (as a percent)	85.00%
Benefits of cash savings retained under tax receivable agreement (as a percent)	15.00%
Increase (decrease) in TRA liability due to valuation allowance recorded	$ 3,300	$ 2,700
Liability under tax receivable agreement	41,720	43,045
Valuation allowance	49,700	$ 50,600
Anticipated payment	$ 600