CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Interest income	$ 1,664,223	$ 1,519,679	$ 1,076,735
Interest expense	606,433	460,865	373,424
Net interest income	1,057,790	1,058,814	703,311
Impairment
Other-than-temporary impairment (OTTI) on securities	30,017	10,334	10,264
Valuation and loss provision (reversal) on loans and real estate owned	60,624	75,758	77,716
Total Impairment Charges	90,641	86,092	87,980
Net interest income after impairment	967,149	972,722	615,331
Servicing revenue, net	528,595	424,349	118,169
Gain on sale of originated mortgage loans, net	89,017	0	0
Other Income
Change in fair value of investments in excess mortgage servicing rights	(58,656)	4,322	(7,297)
Change in fair value of investments in excess mortgage servicing rights, equity method investees	8,357	12,617	16,526
Change in fair value of investments in mortgage servicing rights financing receivables	31,550	66,394	0
Change in fair value of servicer advance investments	(89,332)	84,418	(7,768)
Change in fair value of investments in residential mortgage loans	73,515	0	0
Gain on consumer loans investment	0	0	9,943
Gain on remeasurement of consumer loans investment	0	0	71,250
Gain (loss) on settlement of investments, net	103,842	10,310	(48,800)
Earnings from investments in consumer loans, equity method investees	10,803	25,617	0
Other income (loss), net	(124,336)	4,108	28,483
Total Other Income	(44,257)	207,786	62,337
Operating Expenses
General and administrative expenses	231,579	67,159	38,570
Management fee to affiliate	62,594	55,634	41,610
Incentive compensation to affiliate	94,900	81,373	42,197
Loan servicing expense	43,547	52,330	44,001
Subservicing expense	176,784	166,081	7,832
Total Operating Expenses	609,404	422,577	174,210
Income (Loss) Before Income Taxes	931,100	1,182,280	621,627
Income tax (benefit) expense	(73,431)	167,628	38,911
Net Income (Loss)	1,004,531	1,014,652	582,716
Noncontrolling Interests in Income of Consolidated Subsidiaries	40,564	57,119	78,263
Net income (loss) attributable to common stockholders	$ 963,967	$ 957,533	$ 504,453
Net Income Per Share of Common Stock
Basic (in dollars per share)	$ 2.82	$ 3.17	$ 2.12
Diluted (in dollars per share)	$ 2.81	$ 3.15	$ 2.12
Weighted Average Number of Shares of Common Stock Outstanding
Basic (in shares)	341,268,923	302,238,065	238,122,665
Diluted (in shares)	343,137,361	304,381,388	238,486,772
Dividends declared per Share of Common Stock (in dollars per share)	$ 2	$ 1.98	$ 1.84