Earnings per Common Share (EPS) (Details 1) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Preferred Shares [Line Items]
Securities Issued	1,600	750
Series B
Preferred Shares [Line Items]
Issuance Date	Nov. 10, 2014
Securities Issued	750
Depositary Shares Issued	750,000
Aggregate Liquidation Preference	$ 750
Fixed dividend rate per annum	5.20%
Semi-annual fixed dividend, payment dates	Beginning May 15, 2015
Floating dividend rate per annum	3 month LIBOR+ 3.428%
Quarterly floating dividend, payment dates	Beginning February 15, 2020
Fixed to floating rate, conversion date	Nov. 15, 2019
Series C
Preferred Shares [Line Items]
Issuance Date	Mar. 02, 2015
Securities Issued	850
Depositary Shares Issued	850,000
Aggregate Liquidation Preference	$ 850
Fixed dividend rate per annum	4.90%
Semi-annual fixed dividend, payment dates	Beginning September 15, 2015
Floating dividend rate per annum	3 month LIBOR+ 3.285%
Quarterly floating dividend, payment dates	Beginning June 15, 2020
Fixed to floating rate, conversion date	Mar. 15, 2020