Changes in the Company's carrying value of goodwill by reporting segment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill [Roll Forward]
Goodwill, Gross, Period Start	$ 91,240	$ 90,767
Accumulated Impairment Loss	(29,713)	(29,713)	(29,713)
Additions	0	290
Goodwill, Translation and Purchase Accounting Adjustments	482	183
Goodwill, Gross, End of Period	91,722	91,240
GETS [Member]
Goodwill [Roll Forward]
Goodwill, Gross, Period Start	50,720	50,372
Accumulated Impairment Loss	(15,171)	(15,171)	(15,171)
Additions	0	290
Goodwill, Translation and Purchase Accounting Adjustments	0	58
Goodwill, Gross, End of Period	50,720	50,720
PSS [Member]
Goodwill [Roll Forward]
Goodwill, Gross, Period Start	24,715	24,612
Accumulated Impairment Loss	(8,312)	(8,312)	(8,312)
Additions	0	0
Goodwill, Translation and Purchase Accounting Adjustments	394	103
Goodwill, Gross, End of Period	25,109	24,715
MRI [Member]
Goodwill [Roll Forward]
Goodwill, Gross, Period Start	15,805	15,783
Accumulated Impairment Loss	(6,230)	(6,230)	(6,230)
Additions	0	0
Goodwill, Translation and Purchase Accounting Adjustments	88	22
Goodwill, Gross, End of Period	$ 15,893	$ 15,805