Leases (Summary of Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease right-of-use assets	$ 125,866	$ 146,522
Finance lease assets	12,080	13,179
Total lease assets	137,946	159,701
Current operating lease liabilities	32,929	28,813
Current finance lease liabilities	3,667	3,622
Total current lease liabilities	36,596	32,435
Noncurrent operating lease liabilities	128,319	166,452
Noncurrent finance lease liabilities	23,520	27,872
Total noncurrent lease liabilities	151,839	194,324
Total lease liabilities	$ 188,435	$ 226,759
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property and equipment, net of accumulated depreciation of $286,133 and $261,082	Property and equipment, net of accumulated depreciation of $286,133 and $261,082
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of lease obligations	Current portion of lease obligations
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of lease obligations	Current portion of lease obligations
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Total noncurrent lease liabilities	Total noncurrent lease liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Total noncurrent lease liabilities	Total noncurrent lease liabilities