Earnings Per Share (Details) (Stock options, USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock options
Antidilutive securities excluded from the calculation of earnings per share
Average share price during the reporting period (in dollars per share)	$ 11.89	$ 14.47
Options excluded from the calculation of earnings per share (in shares)	3,744,878
Weighted average exercise price of option during the reporting period (in dollars per share)	$ 12.43