Cash Flow Disclosures And Non Cash Investing And Financing Activities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Interest paid	$ 40,102	$ 54,158	$ 49,148
Cash paid for income taxes	$ 747	$ 53	$ 1,140