Commitments and Contingencies - Components of Operating Lease Expense and Supplemental Cash Flow Information (Parenthetical) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Leases [Abstract]
Sublease Income	$ 0.1

The amount of revenue recognized for the period under subleasing arrangements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=77891322&loc=d3e41620-112719

Name:	us-gaap_OperatingLeasesIncomeStatementSubleaseRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration