Number of new stock issued during the period.

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(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 3: 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(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Stockholders' Equity - Contribution of Class A Common Shares (Details) - USD ($) shares in Millions		3 Months Ended
	Sep. 10, 2018	Mar. 31, 2019
Restricted Stock Units
Limited Partners' Capital Account [Line Items]
Issuance of stock (in shares)		0.1
Class A Common Stock \| Restricted Stock Units
Limited Partners' Capital Account [Line Items]
Issuance of stock (in shares)		0.1
Chief Executive Officer \| Contribution Agreement \| Restricted Stock Units
Limited Partners' Capital Account [Line Items]
Contribution of Class A common stock from related party, fee charged	$ 0
Chief Executive Officer \| Class A Common Stock \| Contribution Agreement
Limited Partners' Capital Account [Line Items]
Contribution of Class A common stock (in shares)		0.1
Contribution of Class A common stock from related party, fee charged		$ 0