Retirement Savings Plan (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Postemployment Benefits [Abstract]
Percentage of employee compensation plus matching contribution	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Percentage of maximum limit for employees to contribute their cash compensation	75.00%
Total plan expenses	$ 1.6	$ 1.6	$ 3.2	$ 3.0