Accounting Policies (Details Textual 2)	1 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2015 USD ($) shares	Jun. 30, 2014 USD ($) shares	Sep. 30, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares	Sep. 30, 2014 shares	Mar. 31, 2014 USD ($)	Jan. 31, 2014 USD ($) project	Dec. 31, 2013 shares	Aug. 31, 2006 property
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares			$ 0	$ 0
Common Unit, Outstanding | shares	1,940,788		1,940,788	2,973,190	2,973,190			3,646,755
Common Units Carrying Value	$ 99,000,000		$ 99,000,000	$ 151,663,000
BCR transaction [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties | property									30
Costs of interest transferred to affiliates of the Company							$ 14,286,000
Number of projects | project							3
Tax indemnity payment accrual						$ 1,646,000
BCR exchange transaction [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A Shares, Units Exchanged | shares	1,032,402	673,565
Common Class A [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares			344,000	224,000
Common Class A [Member] | BCR exchange transaction [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A Shares, Shares Issued | shares	1,032,402	673,565
Exchange of Class A Common Units for Class A shares	$ 344,000	$ 224,000
Noncontrolling Interest [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares			(52,663,000)	(34,358,000)
Noncontrolling Interest [Member] | BCR exchange transaction [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares	52,663,000	34,358,000
Additional Paid-in Capital [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares			$ 52,319,000	$ 34,134,000
Additional Paid-in Capital [Member] | BCR exchange transaction [Member]
Related Party Transaction [Line Items]
Exchange of Class A Common Units for Class A shares	$ 52,319,000	$ 34,134,000