Fair Value - Summary of Assets and Liabilities in Each Level of Fair Value Hierarchy (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Assets
Loans Receivable, Fair Value	$ 11,268,401		$ 10,341,375
Receivables related to Non-Residual Trusts	36,181		43,545
Servicing rights carried at fair value	1,496,073	1,513,830	1,131,124	888,210	766,943	26,382
Derivative instruments	78,262		62,365
Total assets	18,385,950		17,387,529
Derivative liability, fair value, amount not offset against collateral	28,474		5,882
Liabilities
Contingent earn-out payments	0		5,900	10,900
Mortgage-backed debt related to Non-Residual Trusts	651,784		684,778
HMBS related obligations	9,472,666		8,652,746
Total liabilities	17,200,761		16,220,513
Reverse Loans [Member]
Assets
Loans Receivable, Fair Value	9,482,030		8,738,503
Forward Loans in Non-Residual Trusts [Member]
Assets
Loans Receivable, Fair Value	557,786		587,265
Forward Loans Held for Sale [Member]
Assets
Loans Receivable, Fair Value	1,173,588		1,015,607
Charged Off Loans [Member]
Assets
Loans Receivable, Fair Value	54,997		0
Level 1 [Member]
Liabilities
Contingent earn-out payments	0		5,900
Total liabilities	0		5,900
Level 2 [Member]
Assets
Derivative instruments	2,736		19,534
Total assets	1,176,324		1,035,141
Derivative liability, fair value, amount not offset against collateral	28,387		2,127
Liabilities
Total liabilities	28,387		2,127
Level 2 [Member] | Forward Loans Held for Sale [Member]
Assets
Loans Receivable, Fair Value	1,173,588		1,015,607
Level 3 [Member]
Assets
Receivables related to Non-Residual Trusts	36,181		43,545
Servicing rights carried at fair value	1,496,073		1,131,124
Derivative instruments	75,526		42,831
Total assets	11,702,593		10,543,268
Derivative liability, fair value, amount not offset against collateral	87		3,755
Other Accrued Liabilities Carried at Fair Value	14,438		14,789
Liabilities
Mortgage-backed debt related to Non-Residual Trusts	651,784		684,778
HMBS related obligations	9,472,666		8,652,746
Total liabilities	10,138,975		9,356,068
Level 3 [Member] | Reverse Loans [Member]
Assets
Loans Receivable, Fair Value	9,482,030		8,738,503
Level 3 [Member] | Forward Loans in Non-Residual Trusts [Member]
Assets
Loans Receivable, Fair Value	557,786		587,265
Level 3 [Member] | Charged Off Loans [Member]
Assets
Loans Receivable, Fair Value	$ 54,997		$ 0