Employee compensation Restricted Stock Option Awards (Details 1) (Restricted Stock Awards, USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Restricted Stock Awards
Restricted stock awards
Outstanding at the beginning of the period (in shares)	1,799,000
Granted (in shares)	1,068,000
Forfeited (in shares)	(21,000)
Vested (in shares)	(402,000)	[1]
Outstanding at the end of the period (in shares)	2,444,000
Weighted-average grant date fair value
Outstanding at the beginning of the period (in dollars per share)	$ 19.17
Fair value per performance share	$ 25.63
Forfeited (in dollars per share)	$ 22.75
Vested (in dollars per share)	$ 17.90	[1]
Outstanding at the end of the period (in dollars per share)	$ 22.19
Income tax expense	$ 0.3

[1] The vesting of certain restricted stock grants could result in federal and state income tax expense or benefits related to the difference between the market price of the common stock at the date of vesting and the date of grant. For the three months ended March 31, 2014, the Company's recognized income tax expense related to the vesting of restricted stock was immaterial. The Company recognized income tax expense of $0.3 million during the three months ended March 31, 2013 related to restricted stock, which were recorded as adjustments to deferred income taxes.