Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 1,106	$ 1,508	$ 1,232	$ 3,508
Adjustments for changes in:
Foreign exchange translation	148	(1,148)	(2,750)	594
Unrealized holding (losses) gains on marketable securities	(22)	(70)	193	40
Fair value of cash flow hedges	(236)	(228)	(429)	(3)
Reclassification adjustments for items included in net income:
Amortization of unrecognized employee benefit costs	1,361	1,251	2,787	2,517
Realized (gains) from sale of marketable securities	(29)	(6)	(34)	(27)
Realized losses (gains) from settlement of cash flow hedges	59	(29)	62	94
Other comprehensive income (loss)	1,281	(230)	(171)	3,215
Comprehensive income	$ 2,387	$ 1,278	$ 1,061	$ 6,723

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