Revenue - Additional Information (Detail) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($) Contract
Segment Reporting Information [Line Items]
Change in contract liability, revenue recognized \| $	$ 4.5
Centuri
Segment Reporting Information [Line Items]
Number of contracts with original duration more than one year \| Contract	23

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration