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Revenue Recognition (Details) - USD ($) $ in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Oct. 01, 2018 | Sep. 30, 2018
Revenue Recognition |  |  |  |
Retained earnings | $ 957,230 |  |  | $ 948,148
Revenue | 5,037,495 | $ 4,910,832 |  |
Construction Services |  |  |  |
Revenue Recognition |  |  |  |
Revenue | 2,014,500 | $ 2,125,500 |  |
Accounting Standards Update 2014-09 |  |  |  |
Revenue Recognition |  |  |  |
Retained earnings |  |  | $ 7,000 |
Accounting Standards Update 2014-09 | Construction Services |  |  |  |
Revenue Recognition |  |  |  |
Revenue | $ 1,500 |  |  |

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