Description of Business and Basis of Presentation (Accounting Pronouncements) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts and other receivables	$ 342,823			$ 373,471
Allowance for credit losses	38,868	$ 22,151		19,651	$ 20,222
Retained earnings	(5,200,024)			(5,438,930)
Allowance for credit losses
Balance at December 31, 2019	17,830
Amounts charged to expense	15,926	$ 10,655
Balance at March 31, 2020	29,444
Cumulative Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses				$ 9,503
ASU 2016-13
Allowance for credit losses
Balance at December 31, 2019	17,830
Amounts charged to expense	3,280
Write-offs, recoveries and currency impact	(7,002)
Balance at March 31, 2020	29,444
ASU 2016-13 | Adjusted Balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts and other receivables			$ 15,000
Allowance for credit losses			10,000
Retained earnings			$ 22,000
ASU 2016-13 | Cumulative Effect
Allowance for credit losses
Balance at December 31, 2019	$ 15,336