RELATED PARTY TRANSACTIONS AND SIGNIFICANT TRANSACTIONS WITH RBS - Schedule of Related Party Swap Agreements (Details) - Interest rate swaps - Derivatives designated as hedging instruments: - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Schedule of Related Party Swap Agreements [Line Items]
Notional amount	[1]	$ 16,750	$ 5,750
RBSG
Schedule of Related Party Swap Agreements [Line Items]
Notional amount		10,200	5,750
RBSG | Receive-fixed swap
Schedule of Related Party Swap Agreements [Line Items]
Notional amount		$ 6,700	$ 4,750
Minimum fixed interest rate		0.77%	1.66%
Maximum fixed interest rate		2.04%	2.04%
RBSG | Pay-fixed swap
Schedule of Related Party Swap Agreements [Line Items]
Notional amount		$ 3,500	$ 1,000
Minimum fixed interest rate		1.96%	4.18%
Maximum fixed interest rate		4.30%	4.30%

[1] The notional or contractual amount of interest rate derivatives and foreign exchange contracts is the amount upon which interest and other payments under the contract are based. Notional amounts are typically not exchanged. Therefore, notional amounts should not be taken as the measure of credit or market risk, as they tend to greatly overstate the true economic risk of these contracts.