Retirement Plans (Defined Contribution Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 629	$ 776	$ 2,369	$ 2,082
UNITED STATES
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	413	692	1,842	1,810
CANADA
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	54	52	167	172
UNITED KINGDOM
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 162	$ 32	$ 360	$ 100