Stock-Based Compensation Restricted Stock Units (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive shares granted	494,000
Incentive shares ouststanding Aggregate Intrinsic Value (in millions)	$ 21.5
Director restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	1.6
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	2.2
Incentive share awards outstanding at January 1, 2014	752,595
Incentive shares granted	183,890
Incentive share awards vested	(290,912)
Incentive share awards canceled	(19,474)
Incentive shares outstanding at September 30, 2014	626,099
Incentive share awards outstanding Weighted Average Contractual Term (in years)	1 year 0 months 11 days
Incentive shares ouststanding Aggregate Intrinsic Value (in millions)	8.5
Vested and expected to vest at September 30, 2014	595,000
Vested and expected to vest Weighted Average Contractual Term (in years)	0.00
Vested and expected to vest Aggregate Intrinsic Value (in millions)	$ 8.1
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive share awards canceled	(11,021)
Incentive shares outstanding at September 30, 2014	463,146
Director [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive share awards outstanding at January 1, 2014	512,085
Incentive shares granted	122,649
Chief Executive Officer [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive shares outstanding at September 30, 2014	300,000