Retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Retirement Plans [Abstract]
Matching contributions equal to employee's contributions	25.00%	25.00%	25.00%
Maximum contributed compensation	4.00%	4.00%	4.00%
Additional matching contribution	12.50%	12.50%	12.50%
Expense related to retirement savings plan	$ 6.6	$ 7.1	$ 6.6