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Subsequent Events (Details) - Subsequent Event [Member] $ in Millions	May 05, 2020 USD ($)	Apr. 22, 2020 USD ($) ft²
Metropolitan Square Associates Llc [Member]
Subsequent Event [Line Items]
Debt		$ 156.4
Debt Instrument, Interest Rate, Stated Percentage		5.75%
Ownership Percentage		20.00%
Net Rentable Area (in sf) | ft²		654,000
3.343 % unsecured senior notes [Member]
Subsequent Event [Line Items]
Debt	$ 1,250.0
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Senior Notes Pricing	99.85%
Debt Instrument, Interest Rate, Effective Percentage	3.343%
Proceeds from Issuance of Unsecured Debt	$ 1,240.0

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