Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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RELATED PARTY TRANSACTIONS AND SIGNIFICANT TRANSACTIONS WITH RBS - Narrative (Details) - USD ($)			3 Months Ended
	Mar. 07, 2016	Dec. 03, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Nov. 30, 2015
Related Party Transaction [Line Items]
Repurchase of long-term borrowed funds			$ 629,000,000	$ 3,000,000
Gain on extinguishment of debt		$ 3,000,000
Long-term borrowed funds			10,035,000,000		$ 9,886,000,000
RBSG
Related Party Transaction [Line Items]
Repurchase of long-term borrowed funds	$ 125,000,000	$ 750,000,000	125,000,000	0
Long-term borrowed funds			1,125,000,000		1,250,000,000
Payments of ordinary common stock dividends			0	$ 39,000,000
Executive Officers, Family Members, and Their Businesses
Related Party Transaction [Line Items]
Related party loans			126,000,000		$ 136,000,000
Citizens Financial Group, Inc.
Related Party Transaction [Line Items]
Long-term borrowed funds			$ 2,487,000,000
Purchase commitment \| Subordinated Debt \| Citizens Financial Group, Inc.
Related Party Transaction [Line Items]
Long-term borrowed funds						$ 500,000,000
Purchase commitment \| Subordinated Debt \| Citizens Financial Group, Inc. \| Related Party Debt
Related Party Transaction [Line Items]
Long-term borrowed funds						$ 500,000,000