Share-Based Compensation (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2013
Restricted stock activity
Restricted shares outstanding, beginning of period, weighted average price	$ 33.38
Restricted shares outstanding, beginning of period, shares	896,164
Restricted shares granted, weighted average price	$ 15.47
Restricted shares granted, shares	575,080
Restricted shares canceled, weighted average price	$ 34.67
Restricted shares canceled, shares	(3,235)
Restricted shares vested, weighted average price	$ 33.14
Restricted shares vested, shares	(338,372)
Restricted shares outstanding, end of period, weighted average price	$ 24.34
Restricted shares outstanding, end of period, shares	1,129,637.000