Equity - Accumulated Other Comprehensive Income Schedule (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			$ 15,156
Net current period OCI	$ (4,193)	$ (14,890)	5,636	$ (35,498)
Ending balance	20,871		20,871
Cash Flow Hedging [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			15,156	(9,285)
Other comprehensive loss before reclassifications			(4,016)	(50,142)
Reclassifications from AOCI			8,955	15,569
Net current period OCI			5,636	(35,498)
Add OCI attributable to noncontrolling interests			79	7,791
OCI attributable to common stockholders			5,715	(27,707)
Ending balance	$ 20,871	$ (36,992)	20,871	(36,992)
Cash Flow Hedging [Member] \| Fund X [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive loss before reclassifications			867	(1,149)
Reclassifications from AOCI			$ (170)	$ 224

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount after tax of other comprehensive income (loss) attributable to noncontrolling interests.

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