The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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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.

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Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Revenue Recognition (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Oct. 01, 2018
Revenue Recognition
Retained earnings	$ 599,548				$ 948,148				$ 599,548	$ 948,148
Revenue	$ 5,115,600	$ 4,980,200	$ 5,040,000	$ 5,037,500	$ 5,305,800	$ 5,148,000	$ 4,790,900	$ 4,910,800	20,173,329	20,155,512	$ 18,203,402
Construction Services
Revenue Recognition
Revenue									7,778,800	8,238,900	7,295,600
ASU 2014-09
Revenue Recognition
Retained earnings												$ (7,000)
Subcontractor and other direct costs									10,300,000	$ 10,700,000	$ 9,200,000
ASU 2014-09 \| Construction Services
Revenue Recognition
Revenue									$ 4,800