Business Segments and Customer Information - Major Customers (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2020 |
Sep. 30, 2020 |
Jun. 30, 2020 |
Mar. 31, 2020 |
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Revenue, Major Customer [Line Items] | |||||||||||
| Revenues | $ 150,021 | $ 165,505 | $ 168,715 | $ 177,418 | $ 195,271 | $ 198,326 | $ 189,111 | $ 169,919 | $ 661,659 | $ 752,627 | $ 697,218 |
| Percentage of revenue by customer | 100.00% | 100.00% | 100.00% | ||||||||
| DoD | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Revenues | $ 236,397 | $ 304,334 | $ 334,494 | ||||||||
| Percentage of revenue by customer | 36.00% | 41.00% | 48.00% | ||||||||
| Other government | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Revenues | $ 216,957 | $ 205,775 | $ 212,118 | ||||||||
| Percentage of revenue by customer | 33.00% | 27.00% | 30.00% | ||||||||
| Commercial | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Revenues | $ 208,305 | $ 242,518 | $ 150,606 | ||||||||
| Percentage of revenue by customer | 31.00% | 32.00% | 22.00% | ||||||||
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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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