Revenue Recognition - Billing and Financing Components (Details)	3 Months Ended
Mar. 31, 2018
Revenue Recognition
Payment due period from receipt of invoice, per standard billing terms	30 days
Practical expedient, financing components	true

Indicates (true/false) whether practical expedient is elected not to adjust consideration for effect of financing component when transfer and customer payment of good or service occurs within one year or less.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130569-203045

Name:	us-gaap_RevenuePracticalExpedientFinancingComponent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration