Description of Business and Basis of Presentation (Accounting Pronouncements) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts and other receivables	$ 391,748			$ 373,471
Allowance for credit losses	38,114	$ 20,717		19,651	$ 20,222
Retained earnings	(5,188,119)			(5,438,930)
Allowance for credit losses
Balance at December 31, 2019	17,830
Amounts charged to expense	27,941	$ 14,707
Balance at June 30, 2020	32,474
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	12,692
Write-offs, recoveries and currency impact	(13,384)
Balance at June 30, 2020	32,474
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