Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
U.S. Defined Contribution Plan
Defined Contribution Plans
Maximum voluntary tax-deferred contributions, as a percentage of gross compensation	100.00%
Contribution expense recognized for defined contribution plan	$ 6.5	$ 4.8	$ 3.9
International Defined Contribution Plans
Defined Contribution Plans
Contribution expense recognized for defined contribution plan	$ 3.8	$ 2.6	$ 1.9