Revenue Recognition - Billing and Financing Components (Details)	6 Months Ended
Jun. 30, 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 was elected not to adjust consideration for effect of financing component when transfer and customer payment for product or service occurs within one year or less.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130569-203045

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