Incentive Award Plan and Employee Stock Purchase Plan (Details) (USD $)	0 Months Ended	3 Months Ended
	Mar. 04, 2013	Mar. 31, 2013	Mar. 31, 2012
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value	$ 3,200,000
Share-based awards, grants in period	143,182
Stock-based compensation		2,724,000	1,191,000
2010 Employee Stock Purchase Plan (ESPP)
Deferred Compensation Arrangement with Individual, Share-based Payments
Employee stock purchase plan shares issued during period		104,328
Chief Executive Officer
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value	1,000,000
Chief Executive Officer | Performance Based Award
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value	500,000
Other Executive Officers
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value		2,000,000
Other Executive Officers | Performance Based Award
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value		1,000,000
Share-based awards, number of equal vesting components	3
Other Executive Officers | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Share-based Payments
Share-based awards, grant date fair market value		$ 1,000,000