Portfolio Balances and Delinquency Balances Based on 90 days or more Past Due and Net Charge-Offs Related to Managed Portfolio Loans (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Document Period End Date				Sep. 30, 2017
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		$ 285,397		$ 285,397		$ 278,197
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement		2,487		2,487		2,686
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		81	$ 129	268	$ 355
Commercial Portfolio Segment [Member]
Principal Amount Outstanding of Loans Held-in-portfolio		76,960		76,960		78,224
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement		314		314		426
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		22	71	90	183
Residential Portfolio Segment [Member]
Principal Amount Outstanding of Loans Held-in-portfolio		38,730		38,730		38,990
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement		677		677		758
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		15	21	51	80
Consumer Portfolio Segment [Member]
Principal Amount Outstanding of Loans Held-in-portfolio		28,574		28,574		26,084
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement		1,049		1,049		949
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		41	34	120	84
Loans and Finance Receivables [Member]
Principal Amount Outstanding of Loans Held-in-portfolio		144,264		144,264		143,298
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement		2,040		2,040		2,133
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		78	126	261	347
Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	138,774		138,774		131,914
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	96		96		115
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		3	3	7	8
Loans [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	2,359		2,359		2,985
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	351		351		438
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		0	0	0	0
Commercial Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1],[3]	5,385		5,385		4,761
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1],[3]	0		0		0
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		0	0	0	0
Consumer Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	337		337		512
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	0		0		1
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		1	1	2	2
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	133,052		133,052		126,641
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	96		96		$ 114
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	[4]	$ 2	$ 2	$ 5	$ 6

[1] Excludes loans that have completed the foreclosure or short sale process (i.e., involuntary prepayments).

[2] Comprised of unsecuritized residential loans the Company originated and sold to private investors with servicing rights retained. Net charge-offs on these loans are not presented in the table as the data is not reported to the Company by the private investors that own these related loans.

[3] Comprised of commercial mortgages sold through Fannie Mae, Freddie Mac, and Ginnie Mae securitizations, whereby servicing has been retained by the Company.

[4] Net charge-offs are associated with $336 million and $410 million of managed securitized residential loans at September 30, 2017 and December 31, 2016, respectively. Net charge-off data is not reported to the Company for the remaining balance of $132.7 billion and $126.2 billion of managed securitized residential loans at September 30, 2017 and December 31, 2016, respectively.