Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Commitments and Contingencies - Leases (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Leases
Total lease expense	$ 15.7	$ 6.8		$ 32.4	$ 18.8
Willbros Group, Inc
Leases
Total lease expense	$ 7.7		$ 10.5