Stockholders' Equity of REIT and Partners' Capital of OP - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended		0 Months Ended		9 Months Ended		0 Months Ended
	Mar. 26, 2013	Sep. 30, 2010	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Mar. 26, 2013 IPO	Apr. 15, 2014 Underwritten Public Offering	Sep. 30, 2014 Board of Directors	Sep. 30, 2013 Board of Directors	Mar. 26, 2013 Other Investors of Partnership
Distribution Made to Limited Partner [Line Items]
Operating partnership converted into OP units	21,653,813			11,938,420						11,938,420
Shares of the Company's common stock issued (in shares)				16,361	0			16,618	70,000
Shares reserved for issuance			156,397	156,397	0
Stock issued (in shares)		13,200,000		8,500,000		15,180,000	9,200,000
Net proceeds from IPO						$ 282,300
Net proceeds from issuance of shares				$ 221,720	$ 303,600		$ 211,300
Operating partnership units redeemed			26,885	199,856	0
Common stock shares issued				174,467	0