Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill and indefinite life intangible assets:
Goodwill	$ 112,446,000	$ 112,446,000
Trademarks and trade names	24,599,000	24,599,000
Total goodwill and trademarks and trade names	137,045,000	137,045,000
Finite life intangible assets [Abstract]
Gross carrying amount	148,206,000	149,780,000
Accumulated amortization	89,637,000	81,861,000
Weighted average	15 years
Amortization expense	7,800,000	7,900,000	7,100,000
Annual estimated amortization expense [Abstract]
2013	7,000,000
2014	7,000,000
2015	7,000,000
2016	7,000,000
2017	7,000,000
Scanner technology [Member]
Finite life intangible assets [Abstract]
Gross carrying amount	46,482,000	46,482,000
Accumulated amortization	27,533,000	24,490,000
Weighted average	18 years
Developed technology [Member]
Finite life intangible assets [Abstract]
Gross carrying amount	22,500,000	22,500,000
Accumulated amortization	15,909,000	15,085,000
Weighted average	20 years
Distribution network [Member]
Finite life intangible assets [Abstract]
Gross carrying amount	11,598,000	11,598,000
Accumulated amortization	10,093,000	9,591,000
Weighted average	15 years
Trademarks [Member]
Finite life intangible assets [Abstract]
Gross carrying amount	14,086,000	13,784,000
Accumulated amortization	11,660,000	10,925,000
Weighted average	15 years
Other finite life intangible assets [Member]
Finite life intangible assets [Abstract]
Gross carrying amount	53,540,000	55,416,000
Accumulated amortization	$ 24,442,000	$ 21,770,000
Weighted average	8 years