Purchase and Sale Program	12 Months Ended
Dec. 31, 2025
Purchase And Sale Program [Abstract]
Purchase and Sale Program	2. Purchase and Sale Program Beneficiaries may instruct the program agent for the Purchase and Sale Program to withdraw their allocated shares from the Trust for sale through the Purchase and Sale Program. Under this program, 3,370,923; 3,727,301; and 3,778,528 Trust Interests were redeemed, which generated net realized investment gains of $226 million, $229 million and $186 million for the years ended December 31, 2025, 2024 and 2023, respectively. Beneficiaries allocated less than 1,000 shares of Common Stock under the Plan are also entitled to purchase in the Purchase and Sale Program additional shares, subject to a minimum of $250 per purchase (or such lesser amount that would cause the Beneficiary to hold the 1,000 maximum number of Trust Interests). Under this program, 7,705; 10,859; and 17,194 Trust Interests were issued for the years ended December 31, 2025, 2024 and 2023, respectively. The number of Trust Interests allocated to Beneficiaries will be adjusted for any shares of Common Stock purchased or sold in the Purchase and Sale Program such that the Trust Interests held by a Beneficiary will always equal the number of shares of Common Stock allocated to the Beneficiary. Beneficiaries may withdraw all, but generally not less than all, of their allocated shares of Common Stock from the Trust at any time by providing written notice to the Custodian. After the passage of sufficient time, unclaimed cash and Common Stock will be remitted as unclaimed property to the state of last known residence of the Beneficiary, as is the case with other types of unclaimed property. The schedule by which unclaimed property escheats varies by state, but is generally within three to five years of abandonment.

Beneficiaries may instruct the program agent for the Purchase and Sale Program to withdraw their allocated shares from the Trust for sale through the Purchase and Sale Program. Under this program, 3,370,923; 3,727,301; and 3,778,528 Trust Interests were redeemed, which generated net realized investment gains of $226 million, $229 million and $186 million for the years ended December 31, 2025, 2024 and 2023, respectively. Beneficiaries allocated less than 1,000 shares of Common Stock under the Plan are also entitled to purchase in the Purchase and Sale Program additional shares, subject to a minimum of $250 per purchase (or such lesser amount that would cause the Beneficiary to hold the 1,000 maximum number of Trust Interests). Under this program, 7,705; 10,859; and 17,194 Trust Interests were issued for the years ended December 31, 2025, 2024 and 2023, respectively. The number of Trust Interests allocated to Beneficiaries will be adjusted for any shares of Common Stock purchased or sold in the Purchase and Sale Program such that the Trust Interests held by a Beneficiary will always equal the number of shares of Common Stock allocated to the Beneficiary.

Beneficiaries may withdraw all, but generally not less than all, of their allocated shares of Common Stock from the Trust at any time by providing written notice to the Custodian. After the passage of sufficient time, unclaimed cash and Common Stock will be remitted as unclaimed property to the state of last known residence of the Beneficiary, as is the case with other types of unclaimed property. The schedule by which unclaimed property escheats varies by state, but is generally within three to five years of abandonment.