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Selected Balance Sheet Information: Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Selected Balance Sheet Information [Abstract]
Accounts receivable, trade	$ 199,548	$ 146,899
Unbilled revenue	91,085	126,065
Less: Allowance for doubtful accounts	(8,251)	(7,003)	$ (5,162)	$ (2,444)
Accounts receivable, net	$ 282,382	$ 265,961

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Selected Balance Sheet Information [Abstract]

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Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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