Related Party Transactions - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended		1 Months Ended		3 Months Ended	6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Feb. 28, 2013	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2013 Sponsor [Member]	Dec. 31, 2012 Sponsor [Member]	Jun. 30, 2013 Sponsor [Member] Agreement on Investment Opportunities [Member]	Jun. 30, 2013 Sponsor [Member] Agreement on Investment Opportunities [Member]	Dec. 31, 2012 Sponsor [Member] Agreement on Investment Opportunities [Member]	Nov. 30, 2012 Sponsor [Member] Agreement on Investment Opportunities [Member]	Feb. 28, 2013 Advisor [Member]	Nov. 30, 2012 Advisor [Member]	Jun. 30, 2013 Advisor [Member]	Jun. 30, 2013 Advisor [Member]	Dec. 31, 2012 Advisor [Member]	Nov. 30, 2012 Property Manager [Member]	Jun. 30, 2013 Property Manager [Member] Deferred Costs and Other Intangibles [Member]	Jun. 30, 2013 Property Manager [Member] Deferred Costs and Other Intangibles [Member]	Jun. 30, 2013 Property Manager [Member] Operating Expenses [Member]	Jun. 30, 2013 Property Manager [Member] Operating Expenses [Member]	Jun. 30, 2013 Class A Common Shares [Member]	Dec. 31, 2012 Class A Common Shares [Member]	Jun. 30, 2013 Class A Common Shares [Member] Sponsor [Member]	Dec. 31, 2012 Class A Common Shares [Member] Sponsor [Member]	Jun. 30, 2013 Class B Common Shares [Member]	Dec. 31, 2012 Class B Common Shares [Member]	Jun. 30, 2013 Class B Common Shares [Member] Sponsor [Member]	Dec. 31, 2012 Class B Common Shares [Member] Sponsor [Member]	Jun. 30, 2013 Class A Units [Member] Sponsor [Member]	Dec. 31, 2012 Class A Units [Member] Sponsor [Member]	Dec. 31, 2012 3.5% Convertible Perpetual Preferred Units [Member] Sponsor [Member]	Jun. 30, 2013 Series C Convertible Units [Member] Sponsor [Member]	Jun. 30, 2013 Series D Convertible Units [Member] Sponsor [Member]	Jun. 30, 2013 Series E Convertible Units [Member] Sponsor [Member]
Related Party Transaction [Line Items]
Common shares owned																						2.90%	8.50%
Common shares outstanding																				129,433,425	38,663,998			635,075	667	635,075	667
Units outstanding																												13,787,292	32,668		31,085,974	4,375,000	4,375,000
Preferred Units outstanding																														653,492
Equity interest rate				31.60%	17.20%
Advisory management fee in percent											1.75%
Permanent reduction in Advisory management fee	$ 9,800,000									$ 9,800,000	$ 9,800,000
Advisory fees		3,610,000	6,352,000									3,610,000	6,352,000
Accrued management fees														937,000
Property management fee in percent															6.00%
Leasing fee description															One-half month of each lease's annual rent
Fees incurred to the Property Manager																2,461,000	2,888,000	1,061,000	1,264,000
Acquisition and renovation fee in percent									5.00%
Monthly maintenance fee							100,000
Acquisition and renovation fees						44,514,000	72,373,000
Asset acquisition cost						43,189,000	70,053,000
Property acquisition cost						1,325,000	2,320,000
Accrued acquisition and renovation fees							$ 5,082,000	$ 2,811,000