Components of Company's Interest Income and Interest Expense (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest income:
Residential Investment Securities		$ 394,850	$ 570,493	$ 710,567	$ 1,048,732
Commercial investment portfolio	[1]	59,578	52,429	129,765	92,765
Reverse repurchase agreements		2,690	1,355	4,929	1,894
Total interest income		457,118	624,277	845,261	1,143,391
Interest expense:
Repurchase agreements		136,176	101,225	269,067	203,973
Convertible Senior Notes			6,113		29,740
Securitized debt of consolidated VIEs		11,226	5,475	20,259	8,357
Participation sold		157	159	315	318
Other		5,196	100	10,561	104
Total interest expense		152,755	113,072	300,202	242,492
Net interest income		$ 304,363	$ 511,205	$ 545,059	$ 900,899

[1] Includes commercial real estate debt, preferred equity and corporate debt.