Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Company contributions	$ 30.3	$ 26.4	$ 20.6
Deferred Compensation Liability, Current and Noncurrent	48.7	42.7
Deferred compensation plan amounts owed	$ 44.5	$ 41.2