Revenue Recognition (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Standard product warranty, term	1 year
Deferred commissions costs	$ 8,013,000
Customer Concentration Risk [Member]
Significant customers that accounted for greater than 10% of our consolidated revenues	$ 0
Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Concentration of credit risk	0.00%
Maximum [Member]
Payment term	60 days
SaaS Subscription, Term of Contract	2 years
Amortization period	7 years
Minimum [Member]
Payment term	30 days
Amortization period	3 years
Accounting Standards Update 2014-09 [Member]
Deferred Revenue	$ 109,074,000		$ 110,158,000
Deferred commissions costs	12,400,000	$ 11,800,000
Commissions expense recognized	$ 1,000,000
Extended Warranties and Post-Contract Support [Member]
Post-contract support contract, term	12 months
Extended Warranties and Post-Contract Support [Member] | Maximum [Member]
Extended product warranty, term	5 years
Extended Warranties and Post-Contract Support [Member] | Minimum [Member]
Extended product warranty, term	1 year
Extended Warranties and Post-Contract Support [Member] | Accounting Standards Update 2014-09 [Member]
Deferred Revenue	$ 41,300,000	40,300,000
Deferred Revenue, Revenue Recognized	$ 11,800,000
Deferred Revenue, Term	1 year
Deferred Revenue, With an Original Duration of More than One Year	$ 28,800,000
Deferred Revenue, Expected Recognition within Remainder of Year, Percentage	20.00%
Deferred Revenue, Expected Recognition During Year Two, Percentage	28.00%
Deferred Revenue, Expected Recognition During Year Three, Percentage	22.00%
Up-Front Customer Loyalty Programs [Member]
Capitalized customer acquisition costs	$ 113,800,000	107,500,000
Recognized as a reduction of revenue	7,200,000
Volume Commitment Programs [Member]
Contract with Customer, Asset, Net	12,300,000	5,600,000
Contract with Customer, Asset, Reclassified to Receivable	1,300,000
Up-Front Customer Loyalty Programs And Volume Commitment Programs [Member]
Deferred Revenue	$ 878,500,000
Deferred Revenue, Expected Recognition within Remainder of Year, Percentage	23.00%
Deferred Revenue, Expected Recognition During Year Two, Percentage	24.00%
Deferred Revenue, Expected Recognition During Year Three, Percentage	19.00%
Instrument Rebate Programs [Member]
Deferred Revenue	$ 63,700,000	$ 65,900,000
Deferred Revenue, Revenue Recognized	$ 4,600,000
Deferred Revenue, Expected Recognition within Remainder of Year, Percentage	22.00%
Deferred Revenue, Expected Recognition During Year Two, Percentage	26.00%
Deferred Revenue, Expected Recognition During Year Three, Percentage	21.00%
Reagent Rental Programs [Member]
Deferred Revenue	$ 115,900,000
Deferred Revenue, Expected Recognition within Remainder of Year, Percentage	24.00%
Deferred Revenue, Expected Recognition During Year Two, Percentage	28.00%
Deferred Revenue, Expected Recognition During Year Three, Percentage	22.00%