Organization and Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 31, 2017	Jul. 05, 2017	Mar. 17, 2017	Jun. 30, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Common stock, shares authorized (in shares)				500,000,000	500,000,000
Common stock, par value (in dollars per share)				$ 0.01	$ 0.01
Common shares sold (in shares)			17,250,000
Shares issued upon exercise of the underwriters' overallotment option			2,250,000
Net proceeds			$ 300.8
Number of partnership units issued			17,250,000
Subsequent Event
Class of Stock [Line Items]
Common shares sold (in shares)		21,500,000
Shares issued upon exercise of the underwriters' overallotment option	1,500,000
Net proceeds		$ 420.3
Number of partnership units issued		21,500,000