Commitments and Contingencies (Other Commitments) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Operating
2021 (remaining nine months)	$ 2,975
2022	6,756		$ 3,797
2023	6,393		6,756
2024	6,309		6,393
2025	6,297		6,309
2025			6,297
Thereafter	496
Thereafter			496
Total undiscounted cash flows	29,226		30,048
Present value discount	(3,448)		(3,771)
Other adjustments	23,368		23,795
Lease liabilities	49,146		50,072
Finance
2021 (remaining nine months)	4,133
2022	5,604		5,494
2023	5,716		5,604
2024	5,830		5,716
2025	5,946		5,830
2025			5,946
Thereafter	1,567,826
Thereafter			1,567,826
Total undiscounted cash flows	1,595,055		1,596,416
Present value discount	(1,443,833)		(1,445,896)
Other adjustments	0		0
Lease liabilities	151,222		$ 150,520
Operating lease payments made	800	$ 1,100
Finance lease payments made	$ 1,400	$ 1,300
Operating leases, excluding tenant paid leases, weighted average lease term	5 years 3 months 18 days		5 years 7 months 6 days
Operating leases, weighted average incremental borrowing rate, discount rate	5.00%		5.00%
Finance leases, weighted average lease term	96 years 8 months 12 days		97 years
Finance leases, weighted average rate implicit in the lease, discount rate	5.50%		5.50%

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Present value of lessee's discounted obligation for lease payments from finance lease.

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Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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