Summary of Significant Accounting Policies Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 58,464	$ 78,214
Revenues from contracts with customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	53,652	71,022
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 4,812	$ 7,192