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Revenue Accounting for Contracts / Accounting for Joint Ventures (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Mar. 30, 2018 | Mar. 31, 2017 | Mar. 30, 2018 | Mar. 31, 2017
Revenue Accounting For Contracts Accounting For Joint Ventures [Abstract] |  |  |  |
Pass-through costs included in revenues | $ 712,881 | $ 560,566 | $ 1,309,050 | $ 1,233,545

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- Definition Revenue accounting for contracts / accounting for joint ventures. + References No definition available. + Details
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