Significant Accounting Policies (Details)	1 Months Ended	3 Months Ended				12 Months Ended
Significant Accounting Policies (Details)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($) property	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Investment in Commercial Real Estate Properties
Commercial real estate property, net		$ 6,160,645,000				$ 6,071,648,000	$ 6,160,645,000
Depreciation expense (including amortization of capital lease asset)						196,200,000	187,200,000	$ 184,300,000
Impairment charge		0	$ (9,998,000)	$ 0	$ 0	$ 0	(9,998,000)	0
Number of properties expected to be sold \| property			1
Maximum period of cessation of major construction activity to completion of construction project (in years)						1 year
Weighted average amortization period, above-market leases (in years)						4 years 1 month 6 days
Weighted average amortization period, below-market leases (in years)						28 years 9 months 18 days
Weighted average amortization period, in-place leases (in years)						11 years 3 months 18 days
Rental revenue from amortization of acquired leases						$ 20,200,000	24,900,000	21,000,000
Increase (reduction) in interest expense from amortization of above-market rate mortgages						100,000	400,000	$ 2,100,000
Identified intangible assets (included in other assets):
Gross amount		307,824,000				311,830,000	307,824,000
Accumulated amortization		(235,040,000)				(253,064,000)	(235,040,000)
Net		72,784,000				58,766,000	72,784,000
Identified intangible liabilities (included in deferred revenue):
Gross amount		523,228,000				524,793,000	523,228,000
Accumulated amortization		(346,857,000)				(368,738,000)	(346,857,000)
Net		176,371,000				156,055,000	176,371,000
Net Intangible Assets Transferred to Assets Held for Sale						0
Net Intangible Liabilities Transferred to Liabilities Related to Assets Held for Sale						$ 0
16 Court Street
Investment in Commercial Real Estate Properties
Income from amortization of remaining value of below-market mortgage	$ 300,000
Above-market leases \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						1 year
Above-market leases \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						14 years
Below-market leases \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						1 year
Below-market leases \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						14 years
In-place leases \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						1 year
In-place leases \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life of intangible assets (years)						14 years
Building Fee Ownership
Investment in Commercial Real Estate Properties
Estimated useful life (years)						40 years
Building (leasehold interest) \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (years)						40 years
Furniture and fixtures \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (years)						4 years
Furniture and fixtures \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (years)						7 years
Building \| Minimum
Investment in Commercial Real Estate Properties
Estimated useful life (years)						3 years
Building \| Maximum
Investment in Commercial Real Estate Properties
Estimated useful life (years)						40 years
140 Grand Street
Investment in Commercial Real Estate Properties
Impairment charge			$ (10,000,000)
Variable Interest Entity, Primary Beneficiary [Member]
Investment in Commercial Real Estate Properties
Commercial real estate property, net		0				$ 1,400,000,000	0
Mortgages and other loans payable, net		$ 0				$ 494,100,000	$ 0

RECKSON OPERATING PARTNERSHIP LP 10-K