Other Income (Expense) - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Income (Expense) [Line Items]
Effective interest rate	4.90%
Claim settlement	$ 12,548	$ 0	$ 0
Fees and expenses for the SEC investigation	(742)	8,161	0
Litigation settlement amount			1,800
Litigation and insurance proceeds received	$ 0	$ 0	$ 1,814
Minimum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate	3.70%
Maximum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate	11.80%