Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Loan Losses:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 53,311	$ 49,804	$ 19,443
Charged to Cost and Expenses	149,963	74,863	67,432
Charged to Other Accounts	7,270	7,129	2,567
Deductions— Write offs	(100,382)	(78,485)	(39,638)
Balance at End of Period	110,162	53,311	49,804
Deferred tax asset valuation allowance:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	31,978	26,090	26,199
Charged to Cost and Expenses	(24,209)	(2,514)	(5,826)
Charged to Other Accounts	45,834	8,402	5,717
Deductions— Write offs	0	0	0
Balance at End of Period	$ 53,603	$ 31,978	$ 26,090