Revenue Costs to obtain or fulfill a contract (Details) $ in Millions	Mar. 31, 2018 USD ($)
Revenue Recognition [Abstract]
Costs to fulfill a contract	$ 13.6
Accumulated Amortization of Other Deferred Costs	$ 1.3

Accumulated amortization of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs, deferred acquisition costs of insurance companies, or deferred leasing costs for real estate operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AccumulatedAmortizationOfOtherDeferredCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant