Subsequent Events (Details) - USD ($) $ in Millions	Jul. 31, 2017	Jul. 05, 2017	Mar. 17, 2017
Subsequent Event [Line Items]
Common shares sold (in shares)			17,250,000
Proceeds from issuance of stock			$ 300.8
Number of partnership units issued			17,250,000
Shares issued upon exercise of the underwriters' overallotment option			2,250,000
Subsequent Event
Subsequent Event [Line Items]
Common shares sold (in shares)		21,500,000
Proceeds from issuance of stock		$ 420.3
Number of partnership units issued		21,500,000
Shares issued upon exercise of the underwriters' overallotment option	1,500,000