Valuation and Qualifying Accounts (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for Uncollectible Trade Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year		$ 38,580,000	$ 20,061,000	$ 8,280,000
Charged to Costs & Expenses		1,426,000	2,985,000	308,000
Charged to Other Accounts	[1]	(5,295,000)	15,557,000	11,510,000
Deductions	[2]	(2,000)	(23,000)	(37,000)
Balance at End of Year		34,709,000	38,580,000	20,061,000
Deferred tax valuation allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year		1,567,000	5,023,000	6,518,000
Charged to Costs & Expenses		(393,000)	(3,456,000)	(1,495,000)
Balance at End of Year		$ 1,174,000	$ 1,567,000	$ 5,023,000

[1] Expected customer account adjustments charged to revenue and write-offs, net of recoveries.

[2] Represents bad debt recoveries.