Commitments And Contingent Liabilities (Environmental Matters) (Detail) $ in Millions	Mar. 31, 2020 USD ($) entity Potentially_Responsible_Party Plant mi
Site Contingency [Line Items]
Number of miles related to the Passaic River constituting a facility as determined by the US Environmental Protection Agency | mi	17
Number of additional legal entities contacted by EPA in conjunction with Newark Bay study area contamination | entity	11
Passaic River Site Contingency [Member]
Site Contingency [Line Items]
Estimated Cleanup Costs EPA Preferred Method	$ 2,300
Accrual for Environmental Loss Contingencies	$ 65
Number Of Additional Potentially Responsible Parties Directed By New Jersey Department Of Environmental Protection To Arrange Damage Assessment For Lower Passaic River | Potentially_Responsible_Party	56
Passaic River Site Contingency [Member] | Public Service Electric and Gas Company [Member]
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 [Member]
Site Contingency [Line Items]
Accrual for Environmental Loss Contingencies	13
Mgp Remediation Site Contingency [Member] | Public Service Electric and Gas Company [Member]
Site Contingency [Line Items]
Remediation Liability Recorded As Other Current Liabilities	69
Remediation Liability Recorded As Other Noncurrent Liabilities	283
Regulatory Assets	352
Minimum [Member] | Mgp Remediation Site Contingency [Member] | Public Service Electric and Gas Company [Member]
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss	352
Accrual for Environmental Loss Contingencies	352
Maximum [Member] | Mgp Remediation Site Contingency [Member] | Public Service Electric and Gas Company [Member]
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 395