Retirement and Other Benefit Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) Agreement	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Retirement and Other Benefit Plans [Abstract]
Number of defined contribution plans maintained by the company | Agreement	4
Defined contribution retirement plan cost | $	$ 20.4	$ 19.5	$ 16.5