Segment Reporting - Financial Results by Reportable Segment Reconciled to Consolidated Income Before Income Taxes and Total Assets by Reportable Segment Reconciled to Consolidated Total Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net servicing revenue and fees	$ 257,306	$ 88,670	$ 394,315	$ 178,403
Net gains on sales of loans	235,949		314,394
Interest income on loans	36,796	40,453	73,694	79,733
Insurance revenue	18,050	16,803	35,584	36,765
Other revenues	21,132	4,963	28,987	8,829
Total revenues	569,233	150,889	846,974	303,730
Interest expense	68,290	44,523	122,432	90,361
Depreciation and amortization	17,614	11,814	33,947	23,833
Provision for loan losses	95	1,957	1,821	3,526
Other expenses, net	273,050	92,608	467,593	182,526
Total expenses	359,049	150,902	625,793	300,246
Net fair value gains on reverse loans and related HMBS obligations	26,731		63,519
Other fair value gains (losses)	1,656	788	395	5,551
Total other gains	28,387	788	63,914	5,551
Income (loss) before income taxes	238,571	775	285,095	9,035
Total assets	16,930,212	4,086,317	16,930,212	4,086,317	10,978,177
Operating Segments [Member] | Servicing [Member]
Segment Reporting Information [Line Items]
Net servicing revenue and fees	244,432	84,454	369,559	171,269
Other revenues	457	1,033	919	1,819
Total revenues	244,889	85,487	370,478	173,088
Interest expense	5,166	1,228	7,576	2,723
Depreciation and amortization	9,445	8,588	18,302	17,239
Other expenses, net	116,914	70,585	208,962	137,246
Total expenses	131,525	80,401	234,840	157,208
Other fair value gains (losses)	(179)	(246)	(424)	(532)
Total other gains	(179)	(246)	(424)	(532)
Income (loss) before income taxes	113,185	4,840	135,214	15,348
Total assets	3,829,682	1,390,748	3,829,682	1,390,748
Operating Segments [Member] | Asset Receivables Management [Member]
Segment Reporting Information [Line Items]
Net servicing revenue and fees	11,102	9,501	21,192	17,829
Other revenues	69		133
Total revenues	11,171	9,501	21,325	17,829
Depreciation and amortization	1,614	1,893	3,370	3,897
Other expenses, net	5,722	5,545	11,752	10,708
Total expenses	7,336	7,438	15,122	14,605
Income (loss) before income taxes	3,835	2,063	6,203	3,224
Total assets	54,008	58,575	54,008	58,575
Operating Segments [Member] | Insurance [Member]
Segment Reporting Information [Line Items]
Insurance revenue	18,050	16,803	35,584	36,765
Other revenues	6	187	13	489
Total revenues	18,056	16,990	35,597	37,254
Depreciation and amortization	1,168	1,310	2,482	2,657
Other expenses, net	7,934	8,703	16,442	18,123
Total expenses	9,102	10,013	18,924	20,780
Income (loss) before income taxes	8,954	6,977	16,673	16,474
Total assets	212,424	182,034	212,424	182,034
Operating Segments [Member] | Loans and Residuals [Member]
Segment Reporting Information [Line Items]
Interest income on loans	36,796	40,453	73,694	79,733
Other revenues	1		4
Total revenues	36,797	40,453	73,698	79,733
Interest expense	21,800	23,425	44,096	47,403
Provision for loan losses	95	1,957	1,821	3,526
Other expenses, net	4,718	7,322	8,822	14,788
Total expenses	26,613	32,704	54,739	65,717
Other fair value gains (losses)	566	118	404	(177)
Total other gains	566	118	404	(177)
Income (loss) before income taxes	10,750	7,867	19,363	13,839
Total assets	1,549,098	1,655,203	1,549,098	1,655,203
Operating Segments [Member] | Reverse Mortgage [Member]
Segment Reporting Information [Line Items]
Net servicing revenue and fees	6,624		13,372
Net gains on sales of loans	250		4,633
Other revenues	2,366		5,311
Total revenues	9,240		23,316
Interest expense	2,166		5,695
Depreciation and amortization	2,691		5,414
Other expenses, net	40,931		73,454
Total expenses	45,788		84,563
Net fair value gains on reverse loans and related HMBS obligations	26,731		63,519
Total other gains	26,731		63,519
Income (loss) before income taxes	(9,817)		2,272
Total assets	8,351,798		8,351,798
Operating Segments [Member] | Originations [Member]
Segment Reporting Information [Line Items]
Net gains on sales of loans	235,699		309,761
Other revenues	15,527	1,480	17,524	2,098
Total revenues	251,226	1,480	327,285	2,098
Interest expense	8,600		9,306
Depreciation and amortization	2,689	15	4,366	25
Other expenses, net	94,058	1,324	133,475	2,095
Total expenses	105,347	1,339	147,147	2,120
Income (loss) before income taxes	145,879	141	180,138	(22)
Total assets	2,122,345	2,919	2,122,345	2,919
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Other revenues	2,706	2,263	5,122	4,423
Total revenues	2,706	2,263	5,122	4,423
Interest expense	30,558	19,870	55,759	40,235
Depreciation and amortization	7	8	13	15
Other expenses, net	7,625	4,414	24,533	10,261
Total expenses	38,190	24,292	80,305	50,511
Other fair value gains (losses)	1,269	916	415	6,260
Total other gains	1,269	916	415	6,260
Income (loss) before income taxes	(34,215)	(21,113)	(74,768)	(39,828)
Total assets	1,573,710	1,139,514	1,573,710	1,139,514
Eliminations [Member]
Segment Reporting Information [Line Items]
Net servicing revenue and fees	(4,852)	(5,285)	(9,808)	(10,695)
Other revenues			(39)
Total revenues	(4,852)	(5,285)	(9,847)	(10,695)
Other expenses, net	(4,852)	(5,285)	(9,847)	(10,695)
Total expenses	(4,852)	(5,285)	(9,847)	(10,695)
Total assets	$ (762,853)	$ (342,676)	$ (762,853)	$ (342,676)