Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income	$ 22,853	$ 24,595	$ 14,065
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments gains / (losses)	(1,864)	561	(509)
Change in deferred gains on cash flow hedges	0	77	568
Defined benefit pension plans:
Net gain (loss) arising during the year	3,717	(2,170)	(3,628)
Amortization of defined benefit pension items:
Net actuarial loss	861	752	332
Prior service cost	8	9	8
Transition obligation (asset)	0	0	(43)
Amortization of defined benefit pension items:	869	761	297
Defined benefit pension plan adjustments	4,586	(1,409)	(3,331)
Total other comprehensive income (loss), net of tax	2,722	(771)	(3,272)
Comprehensive income	$ 25,575	$ 23,824	$ 10,793