Organization And Basis Of Presentation (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($) ft² state property item	Dec. 31, 2015 USD ($)
Real Estate Properties [Line Items]
Percentage of ownership interest	89.50%	89.50%
Number of properties owned or investment interests	263
Aggregate square feet of the property owned or investment interest \| ft²	29,000,000
Number of states where properties are located \| state	7
Consolidated joint ventures, total real estate assets \| $	$ 193.1	$ 273.4
Consolidated joint ventures, mortgages \| $	70.1	89.5
Consolidated joint ventures, other liabilities \| $	$ 20.7	$ 17.5
Commercial Properties [Member]
Real Estate Properties [Line Items]
Number of tenants \| item	1,800
Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	17
Number of Apartment Units \| item	5,214
Office And Office/Flex Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	94
Office [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	136
Aggregate square feet of the property owned or investment interest \| ft²	23,700,000
Office Flex Buildings [Member]
Real Estate Properties [Line Items]
Aggregate square feet of the property owned or investment interest \| ft²	4,800,000
Flex Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	110
Unconsolidated Joint Venture Office Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	36
Aggregate square feet of the property owned or investment interest \| ft²	5,600,000
Industrial/Warehouse Facilities [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	6
Aggregate square feet of the property owned or investment interest \| ft²	387,400
Unconsolidated Joint Venture Multi-Family Properties [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	10
Number of Apartment Units \| item	3,587
Parking/Retail [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	6
Aggregate square feet of the property owned or investment interest \| ft²	130,100
Unconsolidated Joint Venture Parking/Retail Buildings [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	2
Aggregate square feet of the property owned or investment interest \| ft²	81,700
Unconsolidated Joint Venture Hotel [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	1
Number of Apartment Units \| item	350
Land [Member]
Real Estate Properties [Line Items]
Number of properties owned or investment interests	3

MACK CALI REALTY L P 10-Q