Retirement Savings Plan (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Postemployment Benefits [Abstract]
Percentage of employee compensation plus matching contribution	100.00%
Percentage of maximum limit for employees to contribute their cash compensation	75.00%
Percentage of employee contribution	4.00%
Total plan expenses	$ 1.4	$ 1.1	$ 4.4	$ 3.2