Condensed Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net income	$ 6,527	$ 6,951	$ 30,930	$ 30,067
Other comprehensive income
Change in unrecognized pension and post-retirement benefit costs	0	0	2	0
Income tax (provision) benefit on change in unrecognized pension and post-retirement benefit costs	(4)	(29)	54	(70)
Foreign currency translation adjustments	(168)	803	(6,984)	276
Income tax benefit on foreign currency translation adjustments	118	12	1,111	130
Other comprehensive income (loss)	(54)	786	(5,817)	336
Comprehensive income	6,473	7,737	25,113	30,403
Comprehensive income (loss) attributable to non-controlling interest	(40)	29	(297)	32
Comprehensive income attributable to controlling interest	$ 6,513	$ 7,708	$ 25,410	$ 30,371