Defined Benefit Pension Plans (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
U.S. pension plans
Defined Benefit Plan Disclosure
Contributions by employer	$ 6,000	$ 11,950
Defined benefit plan, estimated future employer contributions	3,000
U.K. pension plans
Defined Benefit Plan Disclosure
Contributions by employer	3,303	$ 3,432
Defined benefit plan, estimated future employer contributions	$ 3,400