Stockholder's Equity - Accumulated Other Comprehensive Income (Loss) - Reclassifications of Accumulated Other Comprehensive Loss (Detail) - USD ($) shares in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Amortization of pension and postretirement items:
Tax benefit	$ (6,080,000)		$ (6,177,000)	$ (17,695,000)	$ (19,683,000)
Derivative, Gain (Loss) on Derivative, Net	(1,824,000)		(403,000)	(1,995,000)	3,088,000
Stock Issued During Period, Shares, Dividend Reinvestment Plan		0.1
Stock Issued During Period, Value, Dividend Reinvestment Plan		$ 136.26
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan		$ 4,500,000
Interest Rate Swap [Member] | Derivatives designated as hedging instrument [Member] | Interest Expense [Member]
Amortization of pension and postretirement items:
Derivative, Gain (Loss) on Derivative, Net	$ 127,000		$ 0	$ 192,000	$ 0