DERIVATIVES - Effect of Derivative Instruments on Net Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI to interest income		$ 626	$ 624	$ 488
Amounts reclassified from OCI to interest expense		(452)	(363)	(443)
Amounts reclassified from OCI to net gain		32	33	70
Amount Reclassified from AOCI
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion of gain (loss) recognized in OCI	[1]	150	334	(59)
Amount Reclassified from AOCI | Net Unrealized Gains (Losses) on Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Amounts reclassified from OCI to interest income	[2]	82	72	56
Amounts reclassified from OCI to interest expense	[2]	(59)	(99)	(235)
Amounts reclassified from OCI to net gain	[3]	$ 0	$ 0	$ (1)

[1] The cumulative effective gains and losses on the Company’s cash flow hedging activities are included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets.

[2] This amount includes both (a) the amortization of effective gains and losses associated with the Company’s terminated cash flow hedges and (b) the current reporting period’s interest settlements realized on the Company’s active cash flow hedges. Both (a) and (b) were previously included on the accumulated other comprehensive loss line item on the Consolidated Balance Sheets and were subsequently recorded as adjustments to the interest expense of the underlying hedged item.

[3] This amount represents hedging gains and losses that have been immediately reclassified from accumulated other comprehensive loss based on the probability that the hedged forecasted transactions would not occur by the originally specified time period. This amount is reflected in the other net gains (losses) line item on the Consolidated Statements of Operations.