Employee Benefit Plans - Narrative (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution on dollar for participant contributions	$ 0.375
Maximum percentage of participant contribution eligible for employer contribution match	6.00%
Employer match up to maximum percentage of eligible compensation	2.25%
United Kingdom Pension Plans of US Entity Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Period of employees average compensation, preceding retirement considered for computation of retirement benefits	2 years
WMS Acquisition
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contributions per employee (as percent)	4.50%