Summary of Significant Accounting Policies - Warranties and Deferred Revenue, Shipping and Handling, Advertising (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Warranty Costs and Deferred Revenue
Period for which parts and labor of purchased equipment is warrantied	1 year
Shipping and handling costs
Shipping and handling costs	$ 23.2	$ 21.3	$ 20.6
Advertising
Advertising expenses	$ 14.0	$ 12.7	$ 12.9

Cost incurred during the reporting period in transporting goods and services to customers. Includes freight-out costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 45
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68080631&loc=d3e61069-111654

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Handling Costs
-URI http://asc.fasb.org/extlink&oid=51575068

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 45
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=68075638&loc=d3e60635-111653

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68058157&loc=d3e18726-107790

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 45
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6408413&loc=d3e221937-122793

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Shipping Costs
-URI http://asc.fasb.org/extlink&oid=51575562

Name:	us-gaap_ShippingHandlingAndTransportationCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration