Basis Of Presentation - Accounts and Other Receivables (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, before Allowance for Credit Loss, Current		$ 99,520	$ 106,153
Other Receivables		4,323	4,441
Allowance for Doubtful Accounts, Premiums and Other Receivables		3,383	3,036
Accounts Receivable, Change in Method, Credit Loss Expense (Reversal)	$ 200
Receivables, Net, Current		100,460	107,558
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, after Allowance for Credit Loss		100,460	107,558	$ 100,500
Receivables, Net, Current		$ 103,843	$ 110,594