Income Taxes (Net Current and Non-current Deferred Tax Assets and Liabilites By Segment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Current deferred tax asset	$ 24,447	$ 21,399
Valuation allowance	(144)	(158)
Current deferred tax liability		(1,190)
Non-current deferred tax asset	67,358	59,846
Valuation allowance	(13,580)	(11,908)
Non-current deferred tax liability	(59,208)	(43,928)
Net deferred tax asset	18,873	24,061
U.S. [Member]
Income Taxes [Line Items]
Current deferred tax asset	19,495	17,652
Current deferred tax liability		(2)
Net current deferred tax asset (liability)	19,495	17,650
Non-current deferred tax asset	26,418	31,414
Non-current deferred tax liability	(39,653)	(36,264)
Net non-current deferred tax asset (liability)	(13,235)	(4,850)
Net deferred tax asset	6,260	12,800
Europe [Member]
Income Taxes [Line Items]
Current deferred tax asset	4,727	3,576
Valuation allowance		(70)
Current deferred tax liability		(1,188)
Net current deferred tax asset (liability)	4,727	2,318
Non-current deferred tax asset	36,652	24,487
Valuation allowance	(10,989)	(9,900)
Non-current deferred tax liability	(17,717)	(5,909)
Net non-current deferred tax asset (liability)	7,946	8,678
Net deferred tax asset	12,673	10,996
Other International [Member]
Income Taxes [Line Items]
Current deferred tax asset	225	171
Valuation allowance	(144)	(88)
Net current deferred tax asset (liability)	81	83
Non-current deferred tax asset	4,288	3,945
Valuation allowance	(2,591)	(2,008)
Non-current deferred tax liability	(1,838)	(1,755)
Net non-current deferred tax asset (liability)	(141)	182
Net deferred tax asset	$ (60)	$ 265