Fair Value Measurements - Carrying and Estimated Fair Value (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Financial assets:
Cash	$ 26	$ 128
Interest bearing deposits with banks	0	1,500
Securities purchased under agreements to resell	4,040	2,392
Financial liabilities:
Long-term debt	1,836	4,340
Derivative financial liabilities	1	12
Level 1 [Member]
Financial assets:
Cash	26	128
Interest bearing deposits with banks		1,500
Securities purchased under agreements to resell	0	0
Real estate secured receivables held for sale	0	0
Due from affiliates	0	0
Financial liabilities:
Due to affiliates carried at fair value		0
Due to affiliates not carried at fair value		0
Derivative financial liabilities	0	0
Level 2 [Member]
Financial assets:
Cash	0	0
Interest bearing deposits with banks		0
Securities purchased under agreements to resell	4,040	2,392
Real estate secured receivables held for sale	0	0
Due from affiliates	124	114
Financial liabilities:
Due to affiliates carried at fair value		485
Due to affiliates not carried at fair value		2,875
Derivative financial liabilities	1	12
Level 3 [Member]
Financial assets:
Cash	0	0
Interest bearing deposits with banks		0
Securities purchased under agreements to resell	0	0
Real estate secured receivables held for sale	275	6,129
Due from affiliates	0	0
Financial liabilities:
Due to affiliates carried at fair value		0
Due to affiliates not carried at fair value		0
Derivative financial liabilities	0	0
Carrying Value [Member]
Financial assets:
Cash	26	128
Interest bearing deposits with banks		1,500
Securities purchased under agreements to resell	4,040	2,392
Real estate secured receivables held for sale	256	5,674
Due from affiliates	124	114
Financial liabilities:
Due to affiliates carried at fair value		485
Due to affiliates not carried at fair value		2,815
Derivative financial liabilities	1	12
Estimated Fair Value [Member]
Financial assets:
Cash	26	128
Interest bearing deposits with banks		1,500
Securities purchased under agreements to resell	4,040	2,392
Real estate secured receivables held for sale	275	6,129
Due from affiliates	124	114
Financial liabilities:
Due to affiliates carried at fair value		485
Due to affiliates not carried at fair value		2,875
Derivative financial liabilities	1	12
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	253	1,317
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	253	1,317
Long-term Debt Carried at Fair Value [Member] \| Estimated Fair Value [Member]
Financial liabilities:
Long-term debt	253	1,317
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	1,784	3,359
Long Term Debt Not Carried at Fair Value [Member] \| Level 3 [Member]
Financial liabilities:
Long-term debt	0	0
Long Term Debt Not Carried at Fair Value [Member] \| Carrying Value [Member]
Financial liabilities:
Long-term debt	1,583	3,023
Long Term Debt Not Carried at Fair Value [Member] \| Estimated Fair Value [Member]
Financial liabilities:
Long-term debt	$ 1,784	$ 3,359

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

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