Employee Benefit Plans - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 United Kingdom Pension Plans of US Entity Defined Benefit [Member]	Dec. 31, 2013 WMS Acquisition
Defined Benefit Plan Disclosure [Line Items]
Period of employees average compensation, preceding retirement considered for computation of retirement benefits		2 years
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%
Maximum annual contributions per employee (as percent)			4.50%