4. Intangible Assets, Goodwill and Other (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Mar. 04, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill	$ 599,300		$ 599,300		$ 555,000
Accumulated impairment loss	(335,200)		(335,200)		(335,200)
Goodwill, net	264,084		264,084		219,770
Goodwill, Acquired During Period	28,700	$ 15,600	44,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				$ 200
Life Science [Member]
Goodwill [Line Items]
Goodwill	250,100		250,100		234,500
Accumulated impairment loss	(41,800)		(41,800)		(41,800)
Goodwill, net	208,300		208,300		192,700
Goodwill, Acquired During Period			15,600
Clinical Diagnostics [Member]
Goodwill [Line Items]
Goodwill	349,200		349,200		320,500
Accumulated impairment loss	(293,400)		(293,400)		(293,400)
Goodwill, net	$ 55,800		55,800		$ 27,100
Goodwill, Acquired During Period			$ 28,700