Stock-based compensation Stock-based Compensation - Performance Vested Awards Return on Investment (Phantom) (Details) (Subsequent Event, 2010 Equity Incentive Plan, Restricted Stock, Modified Market and Performance Vesting Conditions [Member])	0 Months Ended
	Oct. 01, 2014
Share Based Compensation Return On Investment Target One [Member]
Stock-Based Compensation [Line Items]
Return On Investment Target Percentage	175.00%
Vesting Percentage	33.00%
Share Based Compensation Return On Investment Target Two [Member]
Stock-Based Compensation [Line Items]
Return On Investment Target Percentage	200.00%
Vesting Percentage	33.00%
Share Based Compensation Return On Investment Target Three [Member]
Stock-Based Compensation [Line Items]
Return On Investment Target Percentage	250.00%
Vesting Percentage	33.00%
Share Based Compensation Return On Investment Target Five [Member]
Stock-Based Compensation [Line Items]
Return On Investment Target Percentage, Removed from Plan	350.00%