Valuation and Qualifying Accounts (Details) - SEC Schedule, 12-09, Allowance, Credit Loss [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for Doubtful Accounts, Balance at beginning of year		$ 69,433	$ 80,000	$ 59,661
Allowance for doubtful accounts, Charged to Income		26,942	26,220	35,978
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account	[1]	47,521
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment	[1]		(681)	(1,958)
Allowance for Doubtful Accounts, Write-down		51,104	36,106	13,681
Allowance for Doubtful Accounts, Balance at end of year		$ 92,792	$ 69,433	$ 80,000

[1] “Other” primarily includes the effect of fluctuations in foreign currencies and the allowance for doubtful accounts of the businesses acquired and disposed of by the company. For the year ended December 31, 2020, "Other" also includes the effect of adoption of ASU No. 2016-13, refer to Note 1, Significant Accounting Policies, to the consolidated financial statements included in Item 8 of Part II of this 10-K.