Leased Assets and Liabilities (Operating and Finance Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Assets
Operating	$ 200,752	$ 152,554
Finance	10,443	10,683
Total leased assets	211,195	163,237
Liabilities
Current operating lease liabilities	36,060	35,208
Noncurrent operating lease liabilities	177,711	125,294
Accounts payable and accrued liabilities	2,879	2,708
Other noncurrent liabilities	7,927	7,054
Total lease liabilities	$ 224,577	$ 170,264
Maximum
Lessee, Lease, Description [Line Items]
Term of contract	15 years
Option to extend	5 years