Reporting Segments Capital expenditure data by reporting segment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total purchases of property and equipment	$ 8,774	$ 7,529	$ 6,225
GETS [Member]
Segment Reporting Information [Line Items]
Total purchases of property and equipment	5,685	4,832	4,082
PSS [Member]
Segment Reporting Information [Line Items]
Total purchases of property and equipment	2,008	670	837
MRI [Member]
Segment Reporting Information [Line Items]
Total purchases of property and equipment	38	29	116
Corporate [Member]
Segment Reporting Information [Line Items]
Total purchases of property and equipment	1,043	1,998	1,190
Including L R Kimball and DSPCon Property and Equipment Acquired [Member]
Segment Reporting Information [Line Items]
Total purchases of property and equipment			$ 6,225