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	$ 754,524	$ 858,922
Allowance for doubtful accounts	1,455	1,001
Trade accounts receivable from customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	169,219	185,156
BTC receivables from the government
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	585,305	672,627
Other trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 0	$ 1,139