Supplemental Disclosures of Cash Flow Information - Summary of Supplemental Disclosures of Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Disclosure of Cash Flow Information
Cash paid for interest	$ 269,229	$ 288,648	$ 316,094
Cash paid (received) for taxes	61,881	(1,590)	(5,338)
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Real estate owned acquired through foreclosure	158,690	122,911	122,213
Acquisition of trading security received as consideration for sale of servicing rights	0	60,094	0
Residential loans originated to finance the sale of real estate owned	13,389	22,022	52,130
Sales of servicing rights	73,365	9,173	1,056
Servicing Rights Capitalized Upon Sales of Loans [Member]
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Servicing rights acquired, purchased or capitalized	198,865	306,741	214,285
Acquisitions of Servicing Rights [Member]
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Servicing rights acquired, purchased or capitalized	0	5,857	60,406
Servicing Rights Capitalized Upon Deconsolidation Of Residual Trusts [Member]
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Servicing rights capitalized upon deconsolidation of Residual Trusts	$ 0	$ 3,133	$ 0