Real Estate Transactions - Development Activities (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Apr. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Real Estate [Line Items]
Development and redevelopment projects, amount increase							$ 89,000
Development commitments		$ 395,000			$ 395,000		395,000
Depreciation and amortization of real estate, in-place lease, and other intangibles					177,175	$ 141,971	506,172	$ 406,774
Decrease to income (loss) from continuing operations					$ (61,305)	$ 27,762	$ (108,785)	$ (179,711)
Continuing operations basic earnings per share (in dollars per share)					$ (0.10)	$ 0.06	$ (0.17)	$ (0.32)
Continuing operations diluted earnings per share (in dollars per share)					$ (0.10)	$ 0.06	$ (0.17)	$ (0.32)
Massachusetts
Real Estate [Line Items]
Payments to acquire real estate			$ 54,000
Life science
Real Estate [Line Items]
Weighted average remaining useful life (in years)							11 years		15 years
Depreciation and amortization of real estate, in-place lease, and other intangibles					$ 9,000		$ 22,000
Decrease to income (loss) from continuing operations					$ 9,000		$ 22,000
Continuing operations basic earnings per share (in dollars per share)					$ 0.02		$ 0.04
Continuing operations diluted earnings per share (in dollars per share)					$ 0.02		$ 0.04
Life science | Massachusetts
Real Estate [Line Items]
Payments to acquire real estate		$ 180,000	$ 610,000	$ 320,000
Life science | Massachusetts | Subsequent Event
Real Estate [Line Items]
Payments to acquire real estate	$ 73,000