Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Changes in accumulated other comprehensive income (loss) net of tax
Accumulated other comprehensive income, beginning balance			$ (14,957)
Other comprehensive income (loss) before reclassifications			(2,670)
Amounts reclassified from accumulated other comprehensive income			512
Other comprehensive (loss) income net of tax	(152)	(1,372)	(2,158)	(27)
Balance at end of the period	(17,115)		(17,115)
Defined Benefit Pension Plan
Changes in accumulated other comprehensive income (loss) net of tax
Accumulated other comprehensive income, beginning balance			(11,540)
Other comprehensive income (loss) before reclassifications			51
Amounts reclassified from accumulated other comprehensive income			512
Other comprehensive (loss) income net of tax			563
Balance at end of the period	(10,977)		(10,977)
Foreign Currency Translation Gains (Losses)
Changes in accumulated other comprehensive income (loss) net of tax
Accumulated other comprehensive income, beginning balance			(3,876)
Other comprehensive income (loss) before reclassifications			(2,663)
Other comprehensive (loss) income net of tax			(2,663)
Balance at end of the period	(6,539)		(6,539)
Unrealized Gains and (Losses) on Available-for-Sale Securities
Changes in accumulated other comprehensive income (loss) net of tax
Accumulated other comprehensive income, beginning balance			459
Other comprehensive income (loss) before reclassifications			(58)
Other comprehensive (loss) income net of tax			(58)
Balance at end of the period	$ 401		$ 401