Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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

Subsequent Events (Details) - Term Loan - USD ($)	1 Months Ended		2 Months Ended
Subsequent Events (Details) - Term Loan - USD ($)	Mar. 21, 2019	Feb. 28, 2019	Mar. 21, 2019	Dec. 17, 2018
Subsequent Event [Line Items]
Face amount				$ 500,000,000.0
Subsequent Event
Subsequent Event [Line Items]
Repayments of debt	$ 50,000,000.0	$ 75,000,000.0	$ 125,000,000.0