Fair Value of Financial Instruments - Summary of Changes in Fair Value of Investments (Detail) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		$ 13,620	$ 12,282
Energy Marketing Contract Liabilities, Current		27	354
Energy Marketing Contract Liabilities, Total	[1]	39	1,281
Energy Marketing Contracts Assets, Total	[2]	1,372	1,067
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure		12,225	10,793
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure		1,372	1,067
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure		1,395	1,489
Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure		14,992	13,349
Energy Marketing Contract Liabilities, Current			1,281
Equity Securities [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		21	21
Equity Securities [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		21	21
Investments in guaranteed income fund [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		1,395	1,489
Investments in guaranteed income fund [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		1,395	1,489
Investments - Mutual funds and other [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		12,204	10,772
Investments - Mutual funds and other [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value			10,772
Total Investments [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		12,225	10,793
Total Investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		1,395	1,489
Total Investments [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments, at fair value		13,620	12,282
Mark To Market Energy Assets Including Put Option [Member] | Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative Asset		$ 1,372	$ 1,067

[1] (1) Derivative liabilities, at fair value, included less than $0.1 million in current liabilities in the condensed consolidated balance sheet at June 30, 2024 and $0.4 million at December 31, 2023, with the remainder of the balance classified as long-term.

[2]  (1) Derivative assets, at fair value, include $1.2 million in current assets in the condensed consolidated balance sheet at June 30, 2024 and $1.0 million at December 31, 2023, with the remainder of the balance classified as long-term