Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income before noncontrolling interests	$ 114,311	$ 82,595	$ 51,422
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Gains attributable to the fair value of future servicing rights, net of guaranty obligation	(192,825)	(133,631)	(96,515)
Change in the fair value of premiums and origination fees (NOTE 2)	(10,796)	1,959	2,059
Amortization and depreciation	111,427	98,173	80,138
Stock compensation-equity and liability classified	18,477	14,084	9,994
Provision (benefit) for credit losses	(612)	1,644	2,206
Deferred tax expense	37,595	16,919	10,260
Originations of loans held for sale	(12,040,559)	(12,111,553)	(8,103,452)
Sales of loans to third parties	12,697,209	10,688,356	7,326,908
Amortization of deferred loan fees and costs	(1,578)	(1,775)	(1,273)
Amortization of debt issuance costs and debt discount	5,581	3,756	4,174
Origination fees received from loans held for investment	2,104	1,429	2,145
Tax shortfall (benefit) from vesting of equity awards		(1,410)	38
Cash paid to settle risk-sharing obligations	(1,613)	(795)	(2,138)
Changes in:
Servicing fees and other receivables	(5,744)	(623)	1,943
Other assets	(1,014)	2,974	(11,759)
Accounts payable and other liabilities	22,035	7,739	12,415
Performance deposits from borrowers	5,368	(8,556)	8,434
Net cash provided by (used in) operating activities	759,366	(1,338,715)	(703,001)
Cash flows from investing activities
Capital expenditures	(2,478)	(1,413)	(2,525)
Purchase of equity-method investments		(5,000)
Funding of preferred equity investments	(24,835)
Net cash paid to increase ownership interest in a previously held equity method investment	(1,058)
Acquisitions, net of cash received	(6,350)	(12,767)	(23,417)
Purchase of mortgage servicing rights	(43,097)
Originations of loans held for investment	(414,763)	(180,375)	(339,802)
Principal collected on loans held for investment	425,820	172,323	250,104
Net cash provided by (used in) investing activities	(66,761)	(27,232)	(115,640)
Cash flows from financing activities
Borrowings (repayments) of warehouse notes payable, net	(649,845)	1,423,911	774,935
Borrowings of interim warehouse notes payable	325,828	137,397	248,024
Repayments of interim warehouse notes payable	(355,738)	(125,542)	(179,941)
Repayments of note payable	(1,104)	(4,819)	(1,750)
Repayments of secured borrowings			(22,050)
Proceeds from issuance of common stock	3,765	7,553	7,756
Repurchase of common stock	(12,893)	(50,261)	(37,593)
Debt issuance costs	(3,630)	(4,145)	(1,416)
Distributions to noncontrolling interests	(5)
Tax benefit from vesting of equity awards		1,410	(38)
Net cash provided by (used in) financing activities	(693,622)	1,385,504	787,927
Net increase (decrease) in cash, cash equivalents, restricted cash, and restricted cash equivalents (NOTE 2)	(1,017)	19,557	(30,714)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period	214,484	194,927	225,641
Total of cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	213,467	214,484	194,927
Supplemental Disclosure of Cash Flow Information:
Cash paid to third parties for interest	39,311	32,854	23,950
Cash paid for income taxes	$ 34,432	$ 34,832	$ 18,481