Retirement Plans - Schedule of Weighted Average Assets Allocation and Weighted Average Target Allocation (Details) (United Kingdom Subsidiary, UK Plan)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	100.00%
Asset Allocation	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	45.00%
Asset Allocation	43.20%	53.40%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	55.00%
Asset Allocation	56.60%	46.40%
Cash
Defined Benefit Plan Disclosure [Line Items]
Target Asset Allocation	0.00%
Asset Allocation	0.20%	0.20%