Receivables Held for Sale - Summary of Components of Cumulative Lower of Amortized Cost or Fair Value Adjustment (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2017		Mar. 31, 2016
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment				$ 17,000,000
Lower of amortized cost or fair value adjustment on loans held for sale		$ (113,000,000)		68,000,000
Fair Value [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Lower of amortized cost or fair value adjustment on loans held for sale		(108,000,000)		85,000,000
Settlement (Including Short Sales) [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Lower of amortized cost or fair value adjustment on loans held for sale	[1]	(5,000,000)		(17,000,000)
Other Revenue [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[2]			4,000,000
Subsequent to initial transfer to held for sale				51,000,000
Lower of amortized cost or fair value adjustment on loans held for sale		(113,000,000)	[3]	55,000,000
Other Revenue [Member] | Fair Value [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[2]			4,000,000
Subsequent to initial transfer to held for sale				68,000,000
Lower of amortized cost or fair value adjustment on loans held for sale		(108,000,000)	[3]	72,000,000
Other Revenue [Member] | Settlement (Including Short Sales) [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[1],[2]			0
Subsequent to initial transfer to held for sale	[1]			(17,000,000)
Lower of amortized cost or fair value adjustment on loans held for sale	[1]	$ (5,000,000)	[3]	(17,000,000)
Provision for Credit Losses [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[4]			13,000,000
Provision for Credit Losses [Member] | Fair Value [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[4]			13,000,000
Provision for Credit Losses [Member] | Settlement (Including Short Sales) [Member]
Lower of amortized cost or fair value adjustment recorded as a component of:
Initial lower of amortized cost or fair value adjustment	[1],[4]			$ 0

[1] Reflects receivable settlements due to either receivable payoffs (including short sales) or transfers of receivables to REO and reflects either a reversal of the non-credit fair value adjustment previously recorded on these receivables or an additional lower of amortized cost or fair value adjustment required at the time of settlement.

[2] Represents the portion of the initial lower of amortized cost or fair value adjustment attributable to non-credit factors which are recorded as a component of total other revenues in the consolidated statement income (loss) as it reflects the impact on value caused by current marketplace conditions including changes in interest rates.

[3] As all of our receivables are classified as held for sale at March 31, 2017 and December 31, 2016, for the three months ended March 31, 2017 and for all future periods, any lower of amortized cost or fair value adjustments will relate to either changes in fair value subsequent to classification as held for sale or settlements of receivables as discussed above.

[4] Represents the portion of the initial lower of amortized cost or fair value adjustment attributable to credit factors which are recorded as provision for credit losses in the consolidated statement of income (loss).