Fair Value Measurements - Carrying and Estimated Fair Value (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Financial assets:
Cash	$ 173		$ 175
Securities purchased under agreements to resell	4,841		6,924
Financial liabilities:
Long-term debt	17,136		20,839
Level 1 [Member]
Financial assets:
Cash	173		175
Securities purchased under agreements to resell	0		0
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Receivables held for sale	0		0
Due from affiliates	0		0
Financial liabilities:
Due to affiliates carried at fair value	0		0
Due to affiliates not carried at fair value	0		0
Level 1 [Member] | First Lien [Member]
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Level 1 [Member] | Second Lien [Member]
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Level 2 [Member]
Financial assets:
Cash	0		0
Securities purchased under agreements to resell	4,841		6,924
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Receivables held for sale	1,031		0
Due from affiliates	159		86
Financial liabilities:
Due to affiliates carried at fair value	506		496
Due to affiliates not carried at fair value	6,677		8,369
Level 2 [Member] | First Lien [Member]
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Level 2 [Member] | Second Lien [Member]
Real estate secured:
Total real estate secured receivables	0	[1]	0	[1]
Level 3 [Member]
Financial assets:
Cash	0		0
Securities purchased under agreements to resell	0		0
Real estate secured:
Total real estate secured receivables	18,806	[1]	19,995	[1]
Receivables held for sale	873		2,047
Due from affiliates	0		0
Financial liabilities:
Due to affiliates carried at fair value	0		0
Due to affiliates not carried at fair value	0		0
Level 3 [Member] | First Lien [Member]
Real estate secured:
Total real estate secured receivables	17,484	[1]	18,577	[1]
Level 3 [Member] | Second Lien [Member]
Real estate secured:
Total real estate secured receivables	1,322	[1]	1,418	[1]
Carrying Value [Member]
Financial assets:
Cash	173		175
Securities purchased under agreements to resell	4,841		6,924
Real estate secured:
Total real estate secured receivables	21,829	[1]	24,173	[1]
Receivables held for sale	1,840		2,047
Due from affiliates	159		86
Financial liabilities:
Due to affiliates carried at fair value	506		496
Due to affiliates not carried at fair value	6,434		8,246
Carrying Value [Member] | First Lien [Member]
Real estate secured:
Total real estate secured receivables	19,417	[1]	21,514	[1]
Carrying Value [Member] | Second Lien [Member]
Real estate secured:
Total real estate secured receivables	2,412	[1]	2,659	[1]
Fair Value [Member]
Financial assets:
Cash	173		175
Securities purchased under agreements to resell	4,841		6,924
Real estate secured:
Total real estate secured receivables	18,806	[1]	19,995	[1]
Receivables held for sale	1,904		2,047
Due from affiliates	159		86
Financial liabilities:
Due to affiliates carried at fair value	506		496
Due to affiliates not carried at fair value	6,677		8,369
Fair Value [Member] | First Lien [Member]
Real estate secured:
Total real estate secured receivables	17,484	[1]	18,577	[1]
Fair Value [Member] | Second Lien [Member]
Real estate secured:
Total real estate secured receivables	1,322	[1]	1,418	[1]
Long-term Debt Carried at Fair Value [Member] | Level 1 [Member]
Financial liabilities:
Long-term debt	0		0
Long-term Debt Carried at Fair Value [Member] | Level 2 [Member]
Financial liabilities:
Long-term debt	6,976		8,025
Long-term Debt Carried at Fair Value [Member] | Level 3 [Member]
Financial liabilities:
Long-term debt	0		0
Long-term Debt Carried at Fair Value [Member] | Carrying Value [Member]
Financial liabilities:
Long-term debt	6,976		8,025
Long-term Debt Carried at Fair Value [Member] | Fair Value [Member]
Financial liabilities:
Long-term debt	6,976		8,025
Long Term Debt Not Carried at Fair Value [Member] | Level 1 [Member]
Financial liabilities:
Long-term debt	0		0
Long Term Debt Not Carried at Fair Value [Member] | Level 2 [Member]
Financial liabilities:
Long-term debt	9,185		11,232
Long Term Debt Not Carried at Fair Value [Member] | Level 3 [Member]
Financial liabilities:
Long-term debt	1,535		2,069
Long Term Debt Not Carried at Fair Value [Member] | Carrying Value [Member]
Financial liabilities:
Long-term debt	10,160		12,814
Long Term Debt Not Carried at Fair Value [Member] | Fair Value [Member]
Financial liabilities:
Long-term debt	$ 10,720		$ 13,301

[1] The carrying amount of receivables presented in the table above reflects the amortized cost of the receivable, including any accrued interest, less credit loss reserves as well as any charge-offs recorded in accordance with our existing charge-off policies.