CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating activities
Net income	$ 123,120	$ 138,715
Adjustments to reconcile net income to net cash used in operating activities:
Provisions for credit losses	74,395	32,176
Income tax expense	73,430	91,880
Amortization of brokered deposit placement fee	5,179	5,352
Amortization of ABCP Facility upfront fee	502	1,202
Amortization of deferred loan origination costs and fees, net	2,720	1,558
Net amortization of discount on investments	793	883
Interest income on tax indemnification receivable	(4,066)	(3,507)
Depreciation of premises and equipment	2,295	3,436
Amortization of acquired intangibles	261	740
Stock-based compensation expense	12,548	11,210
Unrealized gains on derivative and hedging activities, net	(835)	(3,219)
Gains on sale of loans, net	0	(76,874)
Other adjustments to net income, net	1,101	0
Changes in operating assets and liabilities:
Net decrease in loans held for sale	0	55
Origination of loans held for sale	0	(55)
Increase in accrued interest receivable	(277,582)	(191,011)
Decrease in restricted cash and investments - other	2,053	631
Decrease in other interest-earning assets	1,290	21,392
Decrease in tax indemnification receivable	29,816	14,908
Increase in other assets	(14,591)	(25,214)
Decrease in income tax payable, net	(149,193)	(97,545)
Increase (decrease) in accrued interest payable	2,924	(352)
Decrease in payable due to entity that is a subsidiary of Navient	(808)	(6,542)
Increase (decrease) in other liabilities	7,976	(3,707)
Total adjustments	(229,792)	(222,603)
Total net cash used in operating activities	(106,672)	(83,888)
Investing activities
Loans acquired and originated	(2,234,556)	(2,070,373)
Net proceeds from sales of loans held for investment	5,736	785,481
Proceeds from claim payments	33,892	67,769
Net decrease in loans held for investment	624,040	445,610
Increase in restricted cash and investments - variable interest entities	(8,369)	0
Purchases of available-for-sale securities	(23,362)	(26,237)
Proceeds from sales and maturities of available-for-sale securities	15,492	17,936
Total net cash used in investing activities	(1,587,127)	(779,814)
Financing activities
Brokered deposit placement fee	(2,875)	0
Net increase (decrease) in certificates of deposit	56,272	(140,693)
Net increase (decrease) increase in other deposits	322,959	(72,499)
Issuance costs for collateralized borrowings	(386)	0
Borrowings collateralized by loans in securitization trusts - issued	499,393	0
Borrowings collateralized by loans in securitization trusts - repaid	(40,618)	0
Borrowings under ABCP Facility	26,325	0
Repayment of borrowings under ABCP Facility	(526,500)	0
Fees paid on ABCP Facility	(1,444)	(104)
Excess tax (expense) benefit from the exercise of stock-based awards	(2,249)	5,774
Preferred stock dividends paid	(10,382)	(9,693)
Net cash provided by (used in) financing activities	320,495	(217,215)
Net decrease in cash and cash equivalents	(1,373,304)	(1,080,917)
Cash and cash equivalents at beginning of period	2,416,219	2,359,780
Cash and cash equivalents at end of period	1,042,915	1,278,863
Cash disbursements made for:
Interest	75,165	52,789
Income taxes paid	149,173	91,552
Income taxes received	$ (86)	$ (80)