Reporting Segments Total depreciation and amortization by reporting segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 11,679	$ 10,717	$ 10,346
GETS [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	6,042	6,599	5,730
PSS [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	3,418	1,038	893
MRI [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	295	344	415
Corporate [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 1,924	$ 2,736	$ 3,308