Operating Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Lessee Lease Description [Line Items]
Operating lease right-of-use assets, net	$ 759,574	$ 750,734
Operating lease liabilities	$ 806,976	$ 799,100
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable And Accrued Liabilities Current And Noncurrent	Accounts Payable And Accrued Liabilities Current And Noncurrent
Minimum [Member] | Office Space and Office Equipment [Member]
Lessee Lease Description [Line Items]
Operating leases remaining lease term	1 year
Maximum [Member] | Office Space and Office Equipment [Member]
Lessee Lease Description [Line Items]
Operating leases remaining lease term	14 years