Fair Value of Assets and Liabilities - Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Life Science Property \| Joint Venture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Ownership percentage	55.00%
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	$ 3,493,392	$ 3,299,762
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 6.750% coupon rate, due 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	6.75%
Fair value disclosure	$ 0	299,273
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 4.750% coupon rate, due 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.75%
Fair value disclosure	$ 249,208	249,068
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 9.750% coupon rate, due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	9.75%
Fair value disclosure	$ 986,131	984,359
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 4.750% coupon rate, due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.75%
Fair value disclosure	$ 491,562	490,925
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 4.375% coupon rate, due 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.375%
Fair value disclosure	$ 491,698	0
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 5.625% coupon rate, due 2042
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	5.625%
Fair value disclosure	$ 341,993	341,802
Carrying Amount \| Senior Unsecured Notes \| Senior unsecured notes, 6.250% coupon rate, due 2046
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	6.25%
Fair value disclosure	$ 242,905	242,762
Carrying Amount \| Secured debts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	689,895	691,573
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	3,642,250	3,489,902
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 6.750% coupon rate, due 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	0	303,891
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 4.750% coupon rate, due 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	256,911	256,258
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 9.750% coupon rate, due 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	1,112,840	1,135,800
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 4.750% coupon rate, due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	497,425	502,648
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 4.375% coupon rate, due 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	479,265	0
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 5.625% coupon rate, due 2042
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	338,660	330,120
Estimated Fair Value \| Senior Unsecured Notes \| Senior unsecured notes, 6.250% coupon rate, due 2046
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	248,000	245,000
Estimated Fair Value \| Secured debts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	$ 709,149	$ 716,185

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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