Deferred Costs, Acquired Lease Intangibles and Goodwill - Amortizing Acquired Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Acquired below-market ground leases
Acquired below-market ground leases	$ 396,916	$ 396,916
Less: accumulated amortization	(40,434)	(36,518)
Acquired below-market ground leases, net	356,482	360,398
Acquired below-market leases
Acquired below-market leases	(114,408)	(118,462)
Less: accumulated amortization	68,757	66,012
Acquired below-market leases, net	$ (45,651)	$ (52,450)

Amount of accumulated amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

No definition available.

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Amount before amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

No definition available.

Name:	us-gaap_BelowMarketLeaseGross
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Data Type:	xbrli:monetaryItemType
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Amount after amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

No definition available.

Name:	us-gaap_BelowMarketLeaseNet
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Period Type:	instant

No definition available.

Name:	us-gaap_BelowMarketLeaseNetAbstract
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Accumulated amortization on long-term land leases capitalized as part of real property.

No definition available.

Name:	us-gaap_GroundLeasesAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Gross long-term land leases capitalized as part of real property.

No definition available.

Net long-term land leases which are capitalized as part of real property.

No definition available.

No definition available.

Name:	us-gaap_GroundLeasesNetAbstract
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