Trust Investments (Value Of Securities That Have Been In An Unrealized Loss Position For Less Than And Greater Than 12 Months) (Detail) - USD ($)
Mar. 31, 2018
Dec. 31, 2017
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value $ 885,000,000 $ 603,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses (29,000,000) (8,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value 106,000,000 120,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses (5,000,000) (3,000,000)
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | Domestic Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [1] 117,000,000 40,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [1] (7,000,000) (2,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [1] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [1] 0 0
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | International Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [1] 65,000,000 29,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [1] (7,000,000) (3,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [1] 1,000,000 2,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [1] 0 0
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [1] 182,000,000 69,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [1] (14,000,000) (5,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [1] 1,000,000 2,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [1] 0 0
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | Government [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [2] 364,000,000 343,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [2] (7,000,000) (2,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [2] 80,000,000 91,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [2] (4,000,000) (2,000,000)
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | Corporate [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [3] 339,000,000 191,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [3] (8,000,000) (1,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [3] 25,000,000 27,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [3] (1,000,000) (1,000,000)
Nuclear Decommissioning Trust (NDT) Fund [Member] | Power [Member] | Total Debt Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value 703,000,000 534,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses (15,000,000) (3,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value 105,000,000 118,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses (5,000,000) (3,000,000)
Rabbi Trust [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value 121,000,000 67,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses (3,000,000) (1,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value 31,000,000 34,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses (1,000,000) (1,000,000)
Rabbi Trust [Member] | Domestic Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [4] 0 0
Rabbi Trust [Member] | International Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [4] 0 0
Rabbi Trust [Member] | Equity Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [4] 0 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [4] 0 0
Rabbi Trust [Member] | Government [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [5] 48,000,000 28,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [5] (1,000,000) 0
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [5] 23,000,000 25,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [5] (1,000,000) (1,000,000)
Rabbi Trust [Member] | Corporate [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value [6] 73,000,000 39,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses [6] (2,000,000) (1,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value [6] 8,000,000 9,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses [6] 0 0
Rabbi Trust [Member] | Total Debt Securities [Member]    
Schedule of Trust Investments [Line Items]    
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value 121,000,000 67,000,000
Continuous Unrealized Loss Position, Less Than 12 Months, Gross Unrealized Losses (3,000,000) (1,000,000)
Continuous Unrealized Loss Position, Greater Than 12 Months, Fair Value 31,000,000 34,000,000
Continuous Unrealized Loss Position, Greater Than 12 Months, Gross Unrealized Losses $ (1,000,000) $ (1,000,000)
[1] Equity Securities—Investments in marketable equity securities within the NDT Fund are primarily in common stocks within a broad range of industries and sectors. Effective January 1, 2018, unrealized gains and losses on these securities are recorded in Net Income.
[2] Debt Securities (Government)—Unrealized gains and losses on these securities are recorded in Accumulated Other Comprehensive Income (Loss). The unrealized losses on Power’s NDT investments in U.S. Treasury obligations and Federal Agency mortgage-backed securities were caused by interest rate changes. These investments are guaranteed by the U.S. government or an agency of the U.S. government. Power also has investments in municipal bonds that are primarily in investment grade securities. It is not expected that these securities will settle for less than their amortized cost. Since Power does not intend to sell these securities nor will it be more-likely-than-not required to sell, Power does not consider these debt securities to be other-than-temporarily impaired as of March 31, 2018.
[3] Debt Securities (Corporate)—Unrealized gains and losses on these securities are recorded in Accumulated Other Comprehensive Income (Loss). Power’s investments in corporate bonds are primarily in investment grade securities. It is not expected that these securities would settle for less than their amortized cost. Since Power does not intend to sell these securities nor will it be more-likely-than-not required to sell, Power does not consider these debt securities to be other-than-temporarily impaired as of March 31, 2018.
[4] Equity Securities—Investments in marketable equity securities within the Rabbi Trust Fund are through a mutual fund which invests primarily in common stocks within a broad range of industries and sectors. Effective January 1, 2018, unrealized gains and losses on these securities are recorded in Net Income.
[5] Debt Securities (Government)—Unrealized gains and losses on these securities are recorded in Accumulated Other Comprehensive Income (Loss). The unrealized losses on PSEG’s Rabbi Trust investments in U.S. Treasury obligations and Federal Agency mortgage-backed securities were caused by interest rate changes. These investments are guaranteed by the U.S. government or an agency of the U.S. government. PSEG also has investments in municipal bonds that are primarily in investment grade securities. It is not expected that these securities will settle for less than their amortized cost. Since PSEG does not intend to sell these securities nor will it be more-likely-than-not required to sell, PSEG does not consider these debt securities to be other-than-temporarily impaired as of March 31, 2018.
[6] Debt Securities (Corporate)—Unrealized gains and losses on these securities are recorded in Accumulated Other Comprehensive Income (Loss). PSEG’s investments in corporate bonds are primarily in investment grade securities. It is not expected that these securities would settle for less than their amortized cost. Since PSEG does not intend to sell these securities nor will it be more-likely-than-not required to sell, PSEG does not consider these debt securities to be other-than-temporarily impaired as of March 31, 2018.