CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Interest income	$ 1,519,679	$ 1,076,735	$ 645,072
Interest expense	460,865	373,424	274,013
Net interest income (expense)	1,058,814	703,311	371,059
Impairment
Other-than-temporary impairment (OTTI) on securities	10,334	10,264	5,788
Valuation and loss provision (reversal) on loans and real estate owned	75,758	77,716	18,596
Total Impairment Charges	86,092	87,980	24,384
Net interest income after impairment	972,722	615,331	346,675
Servicing revenue, net	424,349	118,169	0
Other Income
Change in fair value of investments in excess mortgage servicing rights	4,322	(7,297)	38,643
Change in fair value of investments in excess mortgage servicing rights, equity method investees	12,617	16,526	31,160
Change in fair value of investments in mortgage servicing rights financing receivables	66,394	0	0
Change in fair value of servicer advance investments	84,418	(7,768)	(57,491)
Gain on consumer loans investment	0	9,943	43,954
Gain on remeasurement of consumer loans investment	0	71,250	0
Gain (loss) on settlement of investments, net	10,310	(48,800)	(19,626)
Earnings from investments in consumer loans, equity method investees	25,617	0	0
Other income (loss), net	4,108	28,483	5,389
Total Other Income	207,786	62,337	42,029
Operating Expenses
General and administrative expenses	67,159	38,570	61,862
Management fee to affiliate	55,634	41,610	33,475
Incentive compensation to affiliate	81,373	42,197	16,017
Loan servicing expense	52,330	44,001	6,469
Subservicing expense	166,081	7,832	0
Total Operating Expenses	422,577	174,210	117,823
Income (Loss) Before Income Taxes	1,182,280	621,627	270,881
Income tax expense (benefit)	167,628	38,911	(11,001)
Net Income (Loss)	1,014,652	582,716	281,882
Noncontrolling Interests in Income of Consolidated Subsidiaries	57,119	78,263	13,246
Net income (loss) attributable to common stockholders	$ 957,533	$ 504,453	$ 268,636
Net Income Per Share of Common Stock
Basic (in dollars per share)	$ 3.17	$ 2.12	$ 1.34
Diluted (in dollars per share)	$ 3.15	$ 2.12	$ 1.32
Weighted Average Number of Shares of Common Stock Outstanding
Basic (in shares)	302,238,065	238,122,665	200,739,809
Diluted (in shares)	304,381,388	238,486,772	202,907,605
Dividends declared per Share of Common Stock (in dollars per share)	$ 1.98	$ 1.84	$ 1.75