CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net income	$ 94,943	$ 65,915
Adjustments to reconcile net income to net cash used in operating activities:
Provisions for credit losses	25,296	32,602
Income tax expense	51,011	38,875
Amortization of brokered deposit placement fee	2,130	2,615
Amortization of ABCP Facility upfront fee	352	122
Amortization of deferred loan origination costs and fees, net	1,777	1,223
Net amortization of discount on investments	452	342
Interest income on tax indemnification receivable	(1,501)	(1,080)
Depreciation of premises and equipment	2,585	2,104
Amortization of acquired intangibles	117	260
Stock-based compensation expense	9,425	6,216
Unrealized losses on derivative and hedging activities, net	5,364	832
Other adjustments to net income, net	1,258	250
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(153,055)	(147,257)
Decrease in restricted cash and investments, net	5,636	6,778
Increase in other interest-earning assets	(1,228)	(3,606)
Increase in other assets	(13,435)	(11,391)
Decrease in income taxes payable, net	(1,689)	(57,119)
Increase in accrued interest payable	6,146	9,079
Increase in payable due to entity that is a subsidiary of Navient	227	1,169
(Decrease) increase in other liabilities	(39,424)	2,159
Total adjustments	(98,556)	(115,827)
Total net cash used in operating activities	(3,613)	(49,912)
Investing activities
Loans acquired and originated	(1,892,697)	(1,806,583)
Net proceeds from sales of loans held for investment	1,972	3,365
Proceeds from claim payments	11,932	18,528
Net decrease in loans held for investment	506,637	332,414
Increase in restricted cash and investments - variable interest entities	(46,065)	(3,410)
Purchases of available-for-sale securities	(18,481)	(12,090)
Proceeds from sales and maturities of available-for-sale securities	8,170	6,566
Total net cash used in investing activities	(1,428,532)	(1,461,210)
Financing activities
Brokered deposit placement fee	(2,084)	(2,759)
Net decrease in certificates of deposit	(151,003)	(209,411)
Net increase in other deposits	83,018	245,893
Borrowings collateralized by loans in securitization trusts - issued	767,994	0
Borrowings collateralized by loans in securitization trusts - repaid	(99,884)	(20,276)
Issuance costs for collateralized borrowings	(23)	0
Borrowings under ABCP Facility	0	26,325
Fees paid on ABCP Facility	(1,515)	(1,250)
Preferred stock dividends paid	(5,575)	(5,139)
Net cash provided by financing activities	590,928	33,383
Net decrease in cash and cash equivalents	(841,217)	(1,477,739)
Cash and cash equivalents at beginning of period	1,918,793	2,416,219
Cash and cash equivalents at end of period	1,077,576	938,480
Cash disbursements made for:
Interest	54,648	32,766
Income taxes paid	1,426	56,163
Income taxes refunded	$ (32)	$ (86)