Revenue Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018
Revenue, Performance Obligation [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 958,900
Performance obligations to be recognized as revenue within next twelve months	733,700
Contract with Customer, Asset and Liability [Abstract]
Costs and estimated earnings in excess of billings on uncompleted contracts	75,972		$ 76,632
Change in CIE	(660)
Billings on uncompleted contracts in excess of costs and estimated earnings	(118,380)		(120,740)
Change in BIE	2,360
Change in net contract balances	1,700
Contract with Customer, Liability, Revenue Recognized	66,300
Disclosure Customer Contracts Additional Information [Abstract]
Costs incurred and estimated earnings recognized on uncompleted contracts	2,318,949		2,081,799
Billings on uncompleted contracts	2,361,357		2,125,907
Total	(42,408)		(44,108)
Contract Receivable Retainage, Due in Next Twelve Months	20,400		25,900
Contract Receivable Retainage, Due after Next Twelve Months	7,400		$ 2,600
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	318,511	$ 269,910
United States
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	310,137	221,772
Canada
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	7,081	46,860
Other international [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 1,293	$ 1,278