Other Income (Expense) - Narrative (Details) - USD ($)		12 Months Ended
	Oct. 27, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2015
Other Income (Expense) [Line Items]
Effective interest rate		4.90%
Fees and expenses for the SEC investigation		$ (8,161,000)	$ 0	$ 0
Penalties, disgorgements and interest relating to the SEC investigation	$ 3,500,000				$ 3,500,000
Legal fees		4,700,000
Litigation settlement amount	$ 2,750,000	2,750,000	$ 1,800,000
Insurance proceeds received				$ 600,000
Recoveries for litigation and insurance proceeds		$ 0
Minimum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate		3.70%
Maximum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate		11.70%