Supplemental Financial Statement Information (Supplemental Cash Flow Information) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Other Income and Expenses [Abstract]
Cash interest paid	$ 58,501	$ 82,732
Cash income tax payments, net of refunds	2,180	12,176
Finance leased assets obtained in exchange for new lease obligations	$ 19,568	$ 2,756