Separate Financial Information of Subsidiary Guarantors of Indebtedness - Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Cash flows provided by (used in) operating activities	$ 413,268	$ 310,045
Investing activities
Purchases and originations of reverse loans held for investment	(216,948)	(384,816)
Principal payments received on reverse loans held for investment	558,003	473,617
Principal payments received on mortgage loans held for investment	47,678	45,238
Payments received on charged-off loans held for investment	9,205	12,542
Payments received on receivables related to Non-Residual Trusts	6,294	4,011
Proceeds from sales of real estate owned, net	72,581	51,924
Purchases of premises and equipment	(2,312)	(22,638)
Decrease in restricted cash and cash equivalents	989	10,328
Payments for acquisitions of businesses, net of cash acquired	(1,019)	(1,947)
Acquisitions of servicing rights, net	(152)	(8,410)
Proceeds from sale of servicing rights, net	38,817	19,920
Proceeds from sale of business	131,074	0
Capital contributions to subsidiaries and VIEs	0	0
Returns of capital from subsidiaries and VIEs	0	0
Change in due from affiliates	0	0
Other	9,441	(2,174)
Cash flows provided by investing activities	653,651	197,595
Financing activities
Payments on corporate debt	(21,285)	(345)
Extinguishments and settlement of debt	0	(6,327)
Proceeds from securitizations of reverse loans	278,011	410,107
Payments on HMBS related obligations	(890,737)	(590,678)
Issuances of servicing advance liabilities	679,809	815,800
Payments on servicing advance liabilities	(919,933)	(1,043,972)
Net change in warehouse borrowings related to mortgage loans	(175,701)	(59,801)
Net change in warehouse borrowings related to reverse loans	304,472	115,515
Proceeds from financing of servicing rights	0	29,738
Payments on servicing rights related liabilities	(1,709)	(9,639)
Payments on mortgage-backed debt	(66,422)	(52,017)
Other debt issuance costs paid	(2,060)	(5,912)
Capital contributions	0	0
Capital distributions	0	0
Change in due to affiliates	0	0
Other	2,412	(44)
Cash flows used in financing activities	(813,143)	(397,575)
Net increase (decrease) in cash and cash equivalents	253,776	110,065
Cash and cash equivalents at beginning of the period	224,598	202,828
Cash and cash equivalents at end of the period	478,374	312,893
Reportable Legal Entities | Parent Company
Operating activities
Cash flows provided by (used in) operating activities	12,930	(88,861)
Investing activities
Purchases and originations of reverse loans held for investment	0	0
Principal payments received on reverse loans held for investment	0	0
Principal payments received on mortgage loans held for investment	738	654
Payments received on charged-off loans held for investment	0	0
Payments received on receivables related to Non-Residual Trusts	0	0
Proceeds from sales of real estate owned, net	34	4
Purchases of premises and equipment	(159)	(411)
Decrease in restricted cash and cash equivalents	0	9,011
Payments for acquisitions of businesses, net of cash acquired	0	0
Acquisitions of servicing rights, net	0	0
Proceeds from sale of servicing rights, net	0	0
Proceeds from sale of business	0
Capital contributions to subsidiaries and VIEs	(98,803)	0
Returns of capital from subsidiaries and VIEs	145,667	9,410
Change in due from affiliates	32,529	71,923
Other	11,500	162
Cash flows provided by investing activities	91,506	90,753
Financing activities
Payments on corporate debt	(21,285)	0
Extinguishments and settlement of debt		(6,327)
Proceeds from securitizations of reverse loans	0	0
Payments on HMBS related obligations	0	0
Issuances of servicing advance liabilities	0	0
Payments on servicing advance liabilities	0	0
Net change in warehouse borrowings related to mortgage loans	0	0
Net change in warehouse borrowings related to reverse loans	0	0
Proceeds from financing of servicing rights		0
Payments on servicing rights related liabilities	0	0
Payments on mortgage-backed debt	0	0
Other debt issuance costs paid	0	0
Capital contributions	0	0
Capital distributions	0	0
Change in due to affiliates	(82,848)	1,442
Other	(64)	(703)
Cash flows used in financing activities	(104,197)	(5,588)
Net increase (decrease) in cash and cash equivalents	239	(3,696)
Cash and cash equivalents at beginning of the period	773	4,016
Cash and cash equivalents at end of the period	1,012	320
Reportable Legal Entities | Guarantor Subsidiaries
Operating activities
Cash flows provided by (used in) operating activities	133,943	166,164
Investing activities
Purchases and originations of reverse loans held for investment	(216,948)	(384,816)
Principal payments received on reverse loans held for investment	558,003	473,617
Principal payments received on mortgage loans held for investment	0	0
Payments received on charged-off loans held for investment	9,205	12,542
Payments received on receivables related to Non-Residual Trusts	0	0
Proceeds from sales of real estate owned, net	70,619	50,091
Purchases of premises and equipment	(2,153)	(22,227)
Decrease in restricted cash and cash equivalents	530	1,260
Payments for acquisitions of businesses, net of cash acquired	(1,019)	(1,947)
Acquisitions of servicing rights, net	(152)	(8,410)
Proceeds from sale of servicing rights, net	38,817	19,920
Proceeds from sale of business	131,074
Capital contributions to subsidiaries and VIEs	(3,718)	(4,122)
Returns of capital from subsidiaries and VIEs	46,395	6,693
Change in due from affiliates	77,767	43,029
Other	(2,059)	(2,336)
Cash flows provided by investing activities	706,361	183,294
Financing activities
Payments on corporate debt	0	(345)
Extinguishments and settlement of debt		0
Proceeds from securitizations of reverse loans	278,011	410,107
Payments on HMBS related obligations	(890,737)	(590,678)
Issuances of servicing advance liabilities	85,779	128,450
Payments on servicing advance liabilities	(98,865)	(182,557)
Net change in warehouse borrowings related to mortgage loans	(175,701)	(59,801)
Net change in warehouse borrowings related to reverse loans	304,472	115,515
Proceeds from financing of servicing rights		29,738
Payments on servicing rights related liabilities	(1,709)	(9,639)
Payments on mortgage-backed debt	0	0
Other debt issuance costs paid	(1,926)	(5,870)
Capital contributions	23,804	0
Capital distributions	(144,341)	(5,840)
Change in due to affiliates	(40,883)	(64,531)
Other	329	(246)
Cash flows used in financing activities	(661,767)	(235,697)
Net increase (decrease) in cash and cash equivalents	178,537	113,761
Cash and cash equivalents at beginning of the period	221,825	196,812
Cash and cash equivalents at end of the period	400,362	310,573
Reportable Legal Entities | Non-Guarantor Subsidiaries and VIEs
Operating activities
Cash flows provided by (used in) operating activities	266,395	232,742
Investing activities
Purchases and originations of reverse loans held for investment	0	0
Principal payments received on reverse loans held for investment	0	0
Principal payments received on mortgage loans held for investment	46,940	44,584
Payments received on charged-off loans held for investment	0	0
Payments received on receivables related to Non-Residual Trusts	6,294	4,011
Proceeds from sales of real estate owned, net	1,928	1,829
Purchases of premises and equipment	0	0
Decrease in restricted cash and cash equivalents	459	57
Payments for acquisitions of businesses, net of cash acquired	0	0
Acquisitions of servicing rights, net	0	0
Proceeds from sale of servicing rights, net	0	0
Proceeds from sale of business	0
Capital contributions to subsidiaries and VIEs	0	0
Returns of capital from subsidiaries and VIEs	0	0
Change in due from affiliates	8,502	(6,960)
Other	0	0
Cash flows provided by investing activities	64,123	43,521
Financing activities
Payments on corporate debt	0	0
Extinguishments and settlement of debt		0
Proceeds from securitizations of reverse loans	0	0
Payments on HMBS related obligations	0	0
Issuances of servicing advance liabilities	594,030	687,350
Payments on servicing advance liabilities	(821,068)	(861,415)
Net change in warehouse borrowings related to mortgage loans	0	0
Net change in warehouse borrowings related to reverse loans	0	0
Proceeds from financing of servicing rights		0
Payments on servicing rights related liabilities	0	0
Payments on mortgage-backed debt	(66,422)	(52,017)
Other debt issuance costs paid	(134)	(42)
Capital contributions	78,717	4,122
Capital distributions	(47,721)	(10,263)
Change in due to affiliates	4,933	(44,903)
Other	2,147	905
Cash flows used in financing activities	(255,518)	(276,263)
Net increase (decrease) in cash and cash equivalents	75,000	0
Cash and cash equivalents at beginning of the period	2,000	2,000
Cash and cash equivalents at end of the period	77,000	2,000
Eliminations and Reclassifications
Operating activities
Cash flows provided by (used in) operating activities	0	0
Investing activities
Purchases and originations of reverse loans held for investment	0	0
Principal payments received on reverse loans held for investment	0	0
Principal payments received on mortgage loans held for investment	0	0
Payments received on charged-off loans held for investment	0	0
Payments received on receivables related to Non-Residual Trusts	0	0
Proceeds from sales of real estate owned, net	0	0
Purchases of premises and equipment	0	0
Decrease in restricted cash and cash equivalents	0	0
Payments for acquisitions of businesses, net of cash acquired	0	0
Acquisitions of servicing rights, net	0	0
Proceeds from sale of servicing rights, net	0	0
Proceeds from sale of business	0
Capital contributions to subsidiaries and VIEs	102,521	4,122
Returns of capital from subsidiaries and VIEs	(192,062)	(16,103)
Change in due from affiliates	(118,798)	(107,992)
Other	0	0
Cash flows provided by investing activities	(208,339)	(119,973)
Financing activities
Payments on corporate debt	0	0
Extinguishments and settlement of debt		0
Proceeds from securitizations of reverse loans	0	0
Payments on HMBS related obligations	0	0
Issuances of servicing advance liabilities	0	0
Payments on servicing advance liabilities	0	0
Net change in warehouse borrowings related to mortgage loans	0	0
Net change in warehouse borrowings related to reverse loans	0	0
Proceeds from financing of servicing rights		0
Payments on servicing rights related liabilities	0	0
Payments on mortgage-backed debt	0	0
Other debt issuance costs paid	0	0
Capital contributions	(102,521)	(4,122)
Capital distributions	192,062	16,103
Change in due to affiliates	118,798	107,992
Other	0	0
Cash flows used in financing activities	208,339	119,973
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of the period	0	0
Cash and cash equivalents at end of the period	$ 0	$ 0