Separate Financial Information of Subsidiary Guarantors of Indebtedness - Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	$ 779,072	$ 451,950
Investing activities
Purchases and originations of reverse loans held for investment	(382,769)	(896,879)
Principal payments received on reverse loans held for investment	1,431,049	1,122,267
Principal payments received on mortgage loans held for investment	161,419	92,619
Payments received on charged-off loans held for investment	16,997	23,060
Payments received on receivables related to Non-Residual Trusts	14,869	8,110
Proceeds from sales of real estate owned, net	144,212	111,091
Purchases of premises and equipment	(6,141)	(32,866)
Decrease (increase) in restricted cash and cash equivalents	3,489	8,946
Payments for acquisitions of businesses, net of cash acquired	(1,004)	(3,066)
Acquisitions of servicing rights, net	(228)	(9,794)
Proceeds from sales of servicing rights, net	137,301	280,970
Proceeds from sale of business	131,074	0
Cash outflow from deconsolidation of variable interest entities	(100,951)	0
Notes acquired from servicer and protective advance financing facilities	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	6,404	(4,649)
Cash flows provided by investing activities	1,555,721	699,809
Financing activities
Payments and extinguishments of corporate debt	(186,910)	(31,517)
Proceeds from securitizations of reverse loans	464,192	960,157
Payments on HMBS related obligations	(1,992,729)	(1,371,375)
Issuances of servicing advance liabilities	1,482,960	2,179,488
Payments on servicing advance liabilities	(1,785,129)	(2,625,476)
Net change in warehouse borrowings related to mortgage loans	(546,556)	(151,172)
Net change in warehouse borrowings related to reverse loans	428,399	14,139
Proceeds from sales of excess servicing spreads and servicing rights	0	34,307
Payments on servicing rights related liabilities	(1,415)	(22,092)
Payments on mortgage-backed debt	(108,018)	(107,598)
Other debt issuance costs paid	(49,305)	(11,039)
Sale of notes by servicer and protective advance financing facilities	0
Capital contributions	0	0
Capital distributions	0	0
Change in due to affiliates	0	0
Other	21,089	2,189
Cash flows provided by (used in) financing activities	(2,273,422)	(1,129,989)
Net increase (decrease) in cash and cash equivalents	61,371	21,770
Cash and cash equivalents at the beginning of the year	224,598	202,828
Cash and cash equivalents at the end of the year	285,969	224,598
Reportable Legal Entities [Member] | Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(71,410)	(204,359)
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	1,443	940
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	83	30
Purchases of premises and equipment	(1,099)	(595)
Decrease (increase) in restricted cash and cash equivalents	(2)	9,011
Payments for acquisitions of businesses, net of cash acquired	0	0
Acquisitions of servicing rights, net	0	0
Proceeds from sales of servicing rights, net	0	0
Proceeds from sale of business	0
Cash outflow from deconsolidation of variable interest entities	0
Notes acquired from servicer and protective advance financing facilities	0
Capital contributions to subsidiaries and VIEs	(102,897)	0
Returns of capital from subsidiaries and VIEs	223,999	10,991
Change in due from affiliates	171,805	126,883
Other	11,779	309
Cash flows provided by investing activities	305,111	147,569
Financing activities
Payments and extinguishments of corporate debt	(186,910)	(31,037)
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 sales of excess servicing spreads and servicing rights		0
Payments on servicing rights related liabilities	0	0
Payments on mortgage-backed debt	0	0
Other debt issuance costs paid	(32,573)	(528)
Sale of notes by servicer and protective advance financing facilities	0
Capital contributions	0	0
Capital distributions	0	0
Change in due to affiliates	(14,409)	85,801
Other	(76)	(689)
Cash flows provided by (used in) financing activities	(233,968)	53,547
Net increase (decrease) in cash and cash equivalents	(267)	(3,243)
Cash and cash equivalents at the beginning of the year	773	4,016
Cash and cash equivalents at the end of the year	506	773
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	496,899	203,585
Investing activities
Purchases and originations of reverse loans held for investment	(382,769)	(896,879)
Principal payments received on reverse loans held for investment	1,431,049	1,122,267
Principal payments received on mortgage loans held for investment	0	0
Payments received on charged-off loans held for investment	16,997	23,060
Payments received on receivables related to Non-Residual Trusts	0	0
Proceeds from sales of real estate owned, net	140,379	107,347
Purchases of premises and equipment	(5,042)	(32,271)
Decrease (increase) in restricted cash and cash equivalents	2,858	(114)
Payments for acquisitions of businesses, net of cash acquired	(1,004)	(3,066)
Acquisitions of servicing rights, net	(228)	(9,794)
Proceeds from sales of servicing rights, net	137,301	280,970
Proceeds from sale of business	131,074
Cash outflow from deconsolidation of variable interest entities	0
Notes acquired from servicer and protective advance financing facilities	(444,563)
Capital contributions to subsidiaries and VIEs	(9,702)	(26,440)
Returns of capital from subsidiaries and VIEs	124,570	33,233
Change in due from affiliates	13,240	2,372
Other	(5,434)	(4,958)
Cash flows provided by investing activities	1,148,726	595,727
Financing activities
Payments and extinguishments of corporate debt	0	(480)
Proceeds from securitizations of reverse loans	464,192	960,157
Payments on HMBS related obligations	(1,992,729)	(1,371,375)
Issuances of servicing advance liabilities	601,270	228,059
Payments on servicing advance liabilities	(250,473)	(331,376)
Net change in warehouse borrowings related to mortgage loans	(546,556)	(151,172)
Net change in warehouse borrowings related to reverse loans	428,399	14,139
Proceeds from sales of excess servicing spreads and servicing rights		34,307
Payments on servicing rights related liabilities	(1,415)	(22,092)
Payments on mortgage-backed debt	0	0
Other debt issuance costs paid	(15,055)	(7,206)
Sale of notes by servicer and protective advance financing facilities	0
Capital contributions	27,897	0
Capital distributions	(147,657)	(5,430)
Change in due to affiliates	(173,188)	(121,164)
Other	21,328	(666)
Cash flows provided by (used in) financing activities	(1,583,987)	(774,299)
Net increase (decrease) in cash and cash equivalents	61,638	25,013
Cash and cash equivalents at the beginning of the year	221,825	196,812
Cash and cash equivalents at the end of the year	283,463	221,825
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries and VIEs [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	328,522	452,724
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	185,037	91,679
Payments received on charged-off loans held for investment	0	0
Payments received on receivables related to Non-Residual Trusts	14,869	8,110
Proceeds from sales of real estate owned, net	3,809	3,714
Purchases of premises and equipment	0	0
Decrease (increase) in restricted cash and cash equivalents	633	49
Payments for acquisitions of businesses, net of cash acquired	0	0
Acquisitions of servicing rights, net	0	0
Proceeds from sales of servicing rights, net	0	0
Proceeds from sale of business	0
Cash outflow from deconsolidation of variable interest entities	(100,951)
Notes acquired from servicer and protective advance financing facilities	0
Capital contributions to subsidiaries and VIEs	0	0
Returns of capital from subsidiaries and VIEs	0	0
Change in due from affiliates	1,165	(5,899)
Other	0	0
Cash flows provided by investing activities	104,562	97,653
Financing activities
Payments and extinguishments of corporate debt	0	0
Proceeds from securitizations of reverse loans	0	0
Payments on HMBS related obligations	0	0
Issuances of servicing advance liabilities	881,690	1,951,429
Payments on servicing advance liabilities	(1,534,656)	(2,294,100)
Net change in warehouse borrowings related to mortgage loans	0	0
Net change in warehouse borrowings related to reverse loans	0	0
Proceeds from sales of excess servicing spreads and servicing rights		0
Payments on servicing rights related liabilities	0	0
Payments on mortgage-backed debt	(108,018)	(107,598)
Other debt issuance costs paid	(1,677)	(3,305)
Sale of notes by servicer and protective advance financing facilities	444,563
Capital contributions	84,702	26,440
Capital distributions	(200,912)	(38,794)
Change in due to affiliates	1,387	(87,993)
Other	(163)	3,544
Cash flows provided by (used in) financing activities	(433,084)	(550,377)
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of the year	2,000	2,000
Cash and cash equivalents at the end of the year	2,000	2,000
Eliminations and Reclassifications [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	25,061	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	(25,061)	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	(59)	0
Purchases of premises and equipment	0	0
Decrease (increase) 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 sales of servicing rights, net	0	0
Proceeds from sale of business	0
Cash outflow from deconsolidation of variable interest entities	0
Notes acquired from servicer and protective advance financing facilities	444,563
Capital contributions to subsidiaries and VIEs	112,599	26,440
Returns of capital from subsidiaries and VIEs	(348,569)	(44,224)
Change in due from affiliates	(186,210)	(123,356)
Other	59	0
Cash flows provided by investing activities	(2,678)	(141,140)
Financing activities
Payments and extinguishments of corporate debt	0	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 sales of excess servicing spreads and 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
Sale of notes by servicer and protective advance financing facilities	(444,563)
Capital contributions	(112,599)	(26,440)
Capital distributions	348,569	44,224
Change in due to affiliates	186,210	123,356
Other	0	0
Cash flows provided by (used in) financing activities	(22,383)	141,140
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of the year	0	0
Cash and cash equivalents at the end of the year	$ 0	$ 0