Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Allowance for doubtful accounts receivable	$ 39,641	$ 33,901	$ 40,474		$ 29,381
Cumulative Effect on Retained Earnings, before Tax	0	2,706
Provision for Other Credit Losses	112	3,703
Accounts Receivable, Credit Loss Expense (Reversal)	(973)	(811)
Accounts Receivable, Other, Including Dispositions and Foreign Currency	$ 28	(1,078)
Accounting Standards Update 2016-13
Retained Earnings (Accumulated Deficit)		$ (2,112)		$ 2,100
Retained Earnings Effect, Tax			$ 600