Segments Disclosure - Schedule of Each Reportable Segment Information (Details) - Jun. 30, 2015 - USD ($) $ in Thousands	Total	Total
Revenues
Rental income	$ 145,917	$ 289,160
Tenant reimbursement income	12,063	25,551
Fee and other income	4,948	9,443
Total revenues	162,928	324,154
Total expenses	154,543	303,762
Operating income (loss)	8,385	20,392
Income from real estate fund investments	14,072	19,293
Income from unconsolidated joint ventures	2,011	2,986
Unrealized gains on interest rate swaps	21,747	33,725
Interest and other income, net	512	1,366
Interest and debt expense	(42,236)	(84,124)
Net income (loss) before income taxes	4,491	(6,362)
Income tax benefit (expense)	(1,343)	(1,917)
Net income (loss)	3,148	(8,279)
Depreciation and amortization	79,421	153,004
General and administrative	9,133	21,746
Interest and debt expense	42,236	84,124
Transfer taxes due in connection with the sale of shares by a former joint venture partner	5,872	5,872
Acquisition and transaction related costs	2,336	3,475
Income tax (benefit) expense	1,343	1,917
Net Operating Income from unconsolidated joint ventures	4,278	8,059
Income from real estate fund investments	(14,072)	(19,293)
Income from unconsolidated joint ventures	(2,011)	(2,986)
Fee income	(1,780)	(3,315)
Unrealized (gains) losses on interest rate swaps	(21,747)	(33,725)
Interest and other income, net	(512)	(1,366)
Net Operating Income	107,645	209,233
Owned Properties [Member]
Revenues
Rental income	145,349	287,826
Tenant reimbursement income	12,063	25,551
Fee and other income	3,168	6,123
Total revenues	160,580	319,500
Total expenses	138,001	273,652
Operating income (loss)	22,579	45,848
Income from unconsolidated joint ventures	1,985	2,925
Unrealized gains on interest rate swaps	21,747	33,725
Interest and other income, net	91	185
Interest and debt expense	(39,741)	(78,873)
Net income (loss) before income taxes	6,661	3,810
Income tax benefit (expense)	467	7
Net income (loss)	7,128	3,817
Depreciation and amortization	79,119	152,456
General and administrative	(42)
Interest and debt expense	39,741	78,873
Income tax (benefit) expense	(467)	(7)
Net Operating Income from unconsolidated joint ventures	4,138	7,874
Income from unconsolidated joint ventures	(1,985)	(2,925)
Unrealized (gains) losses on interest rate swaps	(21,747)	(33,725)
Interest and other income, net	(91)	(185)
Net Operating Income	105,794	206,178
Other [Member]
Revenues
Rental income	568	1,334
Fee and other income	1,780	3,320
Total revenues	2,348	4,654
Total expenses	16,542	30,110
Operating income (loss)	(14,194)	(25,456)
Income from real estate fund investments	14,072	19,293
Income from unconsolidated joint ventures	26	61
Interest and other income, net	421	1,181
Interest and debt expense	(2,495)	(5,251)
Net income (loss) before income taxes	(2,170)	(10,172)
Income tax benefit (expense)	(1,810)	(1,924)
Net income (loss)	(3,980)	(12,096)
Depreciation and amortization	302	548
General and administrative	9,175	21,746
Interest and debt expense	2,495	5,251
Transfer taxes due in connection with the sale of shares by a former joint venture partner	5,872	5,872
Acquisition and transaction related costs	2,336	3,475
Income tax (benefit) expense	1,810	1,924
Net Operating Income from unconsolidated joint ventures	140	185
Income from real estate fund investments	(14,072)	(19,293)
Income from unconsolidated joint ventures	(26)	(61)
Fee income	(1,780)	(3,315)
Interest and other income, net	(421)	(1,181)
Net Operating Income	$ 1,851	$ 3,055