Commitments And Contingent Liabilities (Environmental Matters) (Detail) $ in Millions	Dec. 31, 2019 USD ($) Potentially_Responsible_Party site entity Plant mi	Dec. 31, 2018 USD ($)
Site Contingency [Line Items]
Percentage of residential gas supply permitted to be recovered in gas hedging by BPU	80.00%
Number of miles related to the Passaic River constituting a facility as determined by the US Environmental Protection Agency | mi	17
Number of legal entities contacted by EPA in conjunction with Newark Bay study area contamination | entity	11
Accrued environmental costs	$ 349	$ 327
Clean Energy Program Current	143	143
Public Service Electric and Gas Company
Site Contingency [Line Items]
Accrued environmental costs	294	268
Regulatory Assets	4,028	3,788
Clean Energy Program Current	143	$ 143
MGP Remediation Site Contingency [Member] | Public Service Electric and Gas Company
Site Contingency [Line Items]
Remediation liability recorded as other current liabilities	68
Remediation liability recorded as environmental costs in noncurrent liabilities	289
Regulatory Assets	$ 357
PSE&G's Former MGP Sites [Member]
Site Contingency [Line Items]
Number of MGP sites identified by registrant and the NJDEP requiring some level of remedial action | site	38
Passaic River Site Contingency [Member]
Site Contingency [Line Items]
Estimated Cleanup Costs EPA Preferred Method	$ 2,300
Aggregate number of PRPs directed by the NJDEP to arrange for natural resource damage assessment and interim compensatory restoration along the lower Passaic River | Potentially_Responsible_Party	56
Accrual for Environmental Loss Contingencies	$ 65
Passaic River Site Contingency [Member] | Public Service Electric and Gas Company
Site Contingency [Line Items]
Number of former generating electric station | Plant	1
Accrual for Environmental Loss Contingencies	$ 52
Passaic River Site Contingency [Member] | PSEG Power LLC
Site Contingency [Line Items]
Accrual for Environmental Loss Contingencies	13
Minimum | MGP Remediation Site Contingency [Member] | Public Service Electric and Gas Company
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss	357
Accrual for Environmental Loss Contingencies	357
Maximum [Member] | MGP Remediation Site Contingency [Member] | Public Service Electric and Gas Company
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 400