Nature of Business and Significant Accounting Policies Nature of Business and Significant Accounting Policies (Details 7) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Changes from Accumulated Other Comprehensive income [Abstract]
Pension plans, beginning balance	$ (2,166)
Pension plans adjustment, before reclassification	(375)
Pension plans, reclassification	163
Pension plans adjustment, after reclassification	(212)	2,961	745
Pension plans, ending balalnce	(2,378)	(2,166)
Cash flow hedges, beginning balance	1,660
Cash flow hedges adjustment, before reclassification	(1,462)
Cash flow hedges, reclassification	727
Cash flow hedges adjustment, after reclassification	(735)	1,660	0
Cash flow hedges, ending balance	925	1,660
Foreign currency translation, beginning balance	26,506
Foreign currency translation adjustment	(88,462)	11,838	20,790
Foreign currency translation, ending balance	(61,956)	26,506
Accumulated other comprehensive earnings, beginning balance	26,000
Other comprehensive earnings, before reclassifications	(90,299)
Other comprehensive earnings, reclassification	890
Other comprehensive earnings, after adjustment	(89,409)	16,459	21,535
Accumulated other comprehensive earnings, ending balance	$ (63,409)	$ 26,000