Stock-based Compensation (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Compensation Cost Not yet Recognized	$ 2.9
Total Compensation Cost Not yet Recognized, Period for Recognition	2 years 1 month 6 days
Non-vested restricted stock award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Compensation Cost Not yet Recognized	$ 5.7
Total Compensation Cost Not yet Recognized, Period for Recognition	2 years 2 months 12 days