Net Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2015

Banking And Thrift [Abstract]

Summary of Capital Adequacy Requirements

		Actual								For Capital Adequacy Purposes								To Be Well Capitalized Under Prompt Corrective Action Provisions
(in millions)		Amount				Ratio				Amount				Ratio				Amount				Ratio
December 31, 2015⁽¹⁾
Total capital (to risk weighted assets)		$	1,593				88.6	%		$	144				8.0	%		$	180				10.0	%
Common Equity Tier 1 capital (no risk weighted assets)⁽¹⁾		$	1,593				88.6	%		$	81				4.5	%		$	117				6.5	%
Tier 1 capital (to risk weighted assets)		$	1,593				88.6	%		$	108				6.0	%		$	144				8.0	%
Tier 1 capital (to average assets)		$	1,593				66.7	%		$	96				4.0	%		$	119				5.0	%
December 31, 2014
Total capital (to risk weighted assets)		$	775				142.0	%		$	44				8.0	%		$	56				10.0	%
Tier 1 capital (to risk weighted assets)		$	775				142.0	%		$	22				4.0	%		$	33				6.0	%
Tier 1 capital (to average assets)		$	775				72.1	%		$	43				4.0	%		$	54				5.0	%