Organization and Business (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	Oct. 19, 2015	Jan. 21, 2015	Aug. 19, 2014	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Common stock, shares authorized (in shares)						500,000,000	500,000,000
Common stock, par value (in dollars per share)						$ 0.01	$ 0.01
Organization and Business
Shares issued upon exercise of the underwriters' overallotment option		2,475,000
Common shares sold		18,975,000
Common share price (in dollars per share)		$ 16.40
Number of partnership units issued		18,975,000
Units
Organization and Business
Net proceeds		$ 297,300
ATM Program | Operating Partnership
Organization and Business
Common shares sold				1,007,695	247,397	1,255,092
Net proceeds				$ 16,438	$ 4,140	$ 20,578
Weighted average price				$ 16.56	$ 16.96	$ 16.63
ATM Program | Maximum
Organization and Business
Aggregate offering price of common stock			$ 150,000
Subsequent events
Organization and Business
Shares issued upon exercise of the underwriters' overallotment option	2,062,500
Common shares sold	15,812,500
Common share price (in dollars per share)	$ 15.00
Net proceeds	$ 226,300
Number of partnership units issued	15,812,500