Amortization of unearned compensation

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- Definition

[Line Items] for Capital Disclosure [Table]

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- Definition

Distributions

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- Definition

Fair value option and measurement.

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- Definition

General Partnership Units Issued in Exchange for Limited Partnership Units

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No definition available.

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- Definition

Net Income Available for Common Unitholders

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- Definition

Partnership units issued in exchange for redeemable units

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- Definition

Units Issued During Period, Value, New Issues

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Units Issued During Period, Value, Unit Options Exercised

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No definition available.

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Units Repurchased and Retired During Period, Value

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No definition available.

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- Definition

Per unit of ownership amount of cash distributions declared to unit-holder of a limited partnership (LP).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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- Definition

Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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- Definition

Carrying amount of the equity interests owned by noncontrolling shareholders, partners, or other equity holders in joint ventures included in the entity's consolidated financial statements.

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-Publisher FASB
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Net Increase or Decrease in balance of noncontrolling interest in the subsidiary during the reporting period.

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Aggregate amount of net income allocated to general partners.

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- Definition

Aggregate amount of net income allocated to limited partners.

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Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements.

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No definition available.

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- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Carrying amount of equity interests owned by noncontrolling shareholders, partners, or other equity holders in one or more of the entities consolidated into the reporting entity's financial statements other than joint ventures, limited partnerships, operating partnerships or interests held by preferred unit holders.

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No definition available.

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The amount of ownership interest of different classes of partners in limited partnership.

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MAALP Capital (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
General Partners' Capital Account [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Units Issued During Period, Value, Unit Options Exercised		$ 625
Total Partnership Capital [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Units Issued During Period, Value, Unit Options Exercised	$ 208	$ 625
Limited Partner [Member]
Capital Disclosure [Line Items]
Distribution Made to Limited Partner, Distributions Declared, Per Unit	$ 0.9600	$ 0.9225
Noncontrolling Interest in Joint Ventures	$ 5,166	$ 2,306	$ 2,306	$ 2,306
Increase (Decrease) in Partners' Capital [Roll Forward]
Dividends, Preferred Stock, Cash	922	922
Other Noncontrolling Interests	2,860
Limited Partner [Member] \| General Partners' Capital Account [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning Balance	6,083,142	6,270,758	6,270,758
Net Income Allocated to General Partners	62,738	48,097
Issuance of units	1,129	105
Units repurchased and retired	(3,023)	(2,912)
Units Issued During Period, Value, Unit Options Exercised	208
General partner units issued in exchange for limited partner units	336	2,780
Units issued in exchange for redeemable units		1,915
Redeemable stock fair market value	(1,351)	965
Adjustment for noncontrolling interest ownership in operating partnership	53	63
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		(233)
Amortization of unearned compensation	4,785	4,024
Distributions	(109,392)	(104,971)
Ending Balance	6,038,625	6,221,216	6,083,142
Limited Partner [Member] \| Total Partnership Capital [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning Balance	6,372,170	6,573,875	6,573,875
Net Income Available for Common Unitholders	65,958	50,820
Other comprehensive (loss) income - derivatives insturments (cash flow hedges)	(3,201)	639
Issuance of units	1,129	105
Units repurchased and retired	(3,023)	(2,912)
General partner units issued in exchange for limited partner units	0	0
Units issued in exchange for redeemable units		1,915
Redeemable stock fair market value	(1,351)	965
Adjustment for noncontrolling interest ownership in operating partnership	0	0
Amortization of unearned compensation	4,785	4,024
Dividends, Preferred Stock, Cash	922	922
Distributions	(113,333)	(108,790)
Ending Balance	6,325,280	6,520,344	6,372,170
Limited Partner [Member] \| Limited Partner [Member]
Capital Disclosure [Line Items]
Noncontrolling Interest in Joint Ventures	2,860
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning Balance	220,043	231,676	231,676
Net Income Allocated to Limited Partners	2,298	1,801
General partner units issued in exchange for limited partner units	(336)	(2,780)
Adjustment for noncontrolling interest ownership in operating partnership	(53)	(63)
Distributions	(3,941)	(3,819)
Ending Balance	218,011	226,815	220,043
Limited Partner [Member] \| AOCI Attributable to Noncontrolling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning Balance	(161)	2,295	2,295
Other comprehensive (loss) income - derivatives insturments (cash flow hedges)	(3,201)	639
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		233
Ending Balance	(3,362)	3,167	(161)
Accumulated Distributions in Excess of Net Income [Member] \| Limited Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of units	0	0	$ 66,840
Dividends, Preferred Stock, Cash	922	922
Preferred Stock Including Additional Paid in Capital [Member] \| Limited Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Ending Balance	$ 66,840	$ 66,840