Summary Of Major Accounting Policies Allowance for credit losses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Jan. 01, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (2,273)	$ (5,860)
Accounts Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	$ 8,500
Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	$ 400
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ 2,273