Loans Receivable - Summary of Changes in Allowance for Loan Losses and Allowance for Losses on Lending Commitments (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Allowance for loan losses
Balance, beginning of period	$ 414	$ 228
Charge-offs	(8)	(1)
Provision	113	187
Other	(28)
Balance, end of period	491	414
Allowance for losses on lending commitments
Balance, beginning of period	188	86
Provision	35	102
Other	(16)
Balance, end of period	$ 207	$ 188