Fair Value of Assets and Liabilities - Liabilities (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Life Science Property | Joint Venture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Ownership percentage	55.00%
Senior Unsecured Notes | Senior unsecured notes, 6.750% coupon rate, due in 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	6.75%
Debt face amount	$ 300,000,000
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	$ 3,792,051,000	$ 3,299,762,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 6.750% coupon rate, due in 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	6.75%
Fair value disclosure	$ 299,470,000	299,273,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 4.750% coupon rate, due in 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.75%
Fair value disclosure	$ 249,138,000	249,068,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 9.750% coupon rate, due in 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	9.75%
Fair value disclosure	$ 985,245,000	984,359,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 4.750% coupon rate, due in 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.75%
Fair value disclosure	$ 491,244,000	490,925,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 4.375% coupon rate, due in 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	4.375%
Fair value disclosure	$ 491,490,000	0
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 5.625% coupon rate, due in 2042
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	5.625%
Fair value disclosure	$ 341,897,000	341,802,000
Carrying Amount | Senior Unsecured Notes | Senior unsecured notes, 6.250% coupon rate, due in 2046
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Coupon rate (percent)	6.25%
Fair value disclosure	$ 242,834,000	242,762,000
Carrying Amount | Secured debts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	690,733,000	691,573,000
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	3,944,284,000	3,489,902,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 6.750% coupon rate, due in 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	302,631,000	303,891,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 4.750% coupon rate, due in 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	258,289,000	256,258,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 9.750% coupon rate, due in 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	1,130,760,000	1,135,800,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 4.750% coupon rate, due in 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	493,445,000	502,648,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 4.375% coupon rate, due in 2031
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	487,870,000	0
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 5.625% coupon rate, due in 2042
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	323,400,000	330,120,000
Estimated Fair Value | Senior Unsecured Notes | Senior unsecured notes, 6.250% coupon rate, due in 2046
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	243,600,000	245,000,000
Estimated Fair Value | Secured debts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value disclosure	$ 704,289,000	$ 716,185,000