Cover Page Explanatory Note (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018
Contract assets	$ 619,703
Deferred income taxes	159,071				$ 0
Accounts Receivable, Net, Current	47,784				21,910
Retained earnings	$ 1,259,984				305,208
Accounting Standards Update 2014-09 (Topic 606) [Member]
Contract assets					557,377
Deferred income taxes		$ 135,535	$ 137,872	$ 140,197	184,901
Accounts Receivable, Net, Current		41,640	52,933	50,346	41,810
Retained earnings		1,156,120	1,094,533	1,035,316	997,250
Restatement Adjustment [Member]
Contract assets				(84,000)	87,600
Deferred income taxes				19,400	19,400
Accounts Receivable, Net, Current				3,700
Retained earnings				68,300	68,300
Restatement Adjustment [Member] \| Accounting Standards Update 2014-09 (Topic 606) [Member]
Deferred income taxes		(19,366)	(19,366)	(19,366)	(29,224)
Accounts Receivable, Net, Current		(3,653)	(3,653)	(3,653)	0
Retained earnings		$ (68,257)	$ (68,257)	$ (68,257)	$ (68,257)

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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