Available-for-sale Securities, Gross Unrealized Gain

$ 287,500,000

$ 240,300,000

Available-for-sale Securities, Gross Unrealized Loss

58,800,000

58,500,000

Investments [Abstract]

Equity investments in unconsolidated subsidiaries

84,500,000

87,100,000

Miscellaneous investments

43,000,000

41,900,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

14,972,000

33,281,000

1,460,778,000

1,445,197,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Commingled funds

469,608,000

457,986,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | International equity funds

78,812,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Private equity investments

74,222,000

52,143,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Real estate

45,075,000

45,564,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Government securities

34,379,000

34,304,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | U.S. corporate bonds

80,196,000

80,275,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | International corporate bonds

17,696,000

15,025,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Municipal bonds

235,751,000

241,112,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Asset-backed securities

9,226,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Mortgage-backed securities

23,554,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost | Common stock

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

377,287,000

406,695,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value

14,972,000

33,281,000

1,689,441,000

^[1]

1,627,026,000

^[2]

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Commingled funds

471,388,000

452,227,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | International equity funds

85,856,000

81,671,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Private equity investments

97,004,000

62,696,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Real estate

63,973,000

57,368,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Government securities

29,726,000

27,628,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | U.S. corporate bonds

79,248,000

83,538,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | International corporate bonds

17,613,000

15,358,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Municipal bonds

240,907,000

232,016,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Asset-backed securities

9,347,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Mortgage-backed securities

23,696,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Common stock

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

555,711,000

581,243,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1

14,972,000

33,281,000

570,683,000

614,524,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Commingled funds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | International equity funds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Private equity investments

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Real estate

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Government securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | U.S. corporate bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | International corporate bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Municipal bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Asset-backed securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Mortgage-backed securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Common stock

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

555,711,000

581,243,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2

957,781,000

892,438,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Commingled funds

471,388,000

452,227,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | International equity funds

85,856,000

81,671,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Private equity investments

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Real estate

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Government securities

29,726,000

27,628,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | U.S. corporate bonds

79,248,000

83,538,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | International corporate bonds

17,613,000

15,358,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Municipal bonds

240,907,000

232,016,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Asset-backed securities

9,347,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Mortgage-backed securities

23,696,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Common stock

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3

160,977,000

120,064,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Commingled funds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | International equity funds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Private equity investments

97,004,000

62,696,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Real estate

63,973,000

57,368,000

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Government securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | U.S. corporate bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | International corporate bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Municipal bonds

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Asset-backed securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Mortgage-backed securities

Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Common stock