Long-Term Debt - Outstanding Long-Term Debt (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total long-term debt	$ (1,200,000)	$ (1,200,000)
Debt Instrument, Unused Borrowing Capacity, Amount	255,000
Total Long-term debt	1,191,478	1,205,580
Less: current maturities	(18,522)	(18,505)
Less: debt issuance costs	3,329	3,753
Total long-term debt, net of current maturities	$ 1,172,956	1,187,075
Debt Instrument, Interest Rate, Stated Percentage	6.54%
Proceeds from Issuance of Senior Long-Term Debt	$ 550,000
5.93% note, due October 31, 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.93%
Debt instrument, maturity date	Oct. 31, 2023
5.68% note, due June 30, 2026 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (5,800)	(8,700)
Debt Instrument, Interest Rate, Stated Percentage	5.68%
Debt instrument, maturity date	Jun. 30, 2026
6.43% note, due May 2, 2028 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (2,800)	(3,500)
Debt Instrument, Interest Rate, Stated Percentage	6.43%
Debt instrument, maturity date	May 02, 2028
3.73% note, due December 16, 2028 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (10,000)	(10,000)
Debt Instrument, Interest Rate, Stated Percentage	3.73%
Debt instrument, maturity date	Dec. 16, 2028
3.88% note, due May 15, 2029 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (25,000)	(30,000)
Debt Instrument, Interest Rate, Stated Percentage	3.88%
Debt instrument, maturity date	May 15, 2029
3.25% note, due April 30, 2032 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (54,250)	(59,500)
3.48% note, due May 31, 2038 [Member]
Debt Instrument [Line Items]
Total long-term debt	(50,000)	(50,000)
Uncollateralized Senior Note Due November Two Thousand Thirty Eight [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (50,000)	(50,000)
Debt Instrument, Interest Rate, Stated Percentage	3.58%
Debt instrument, maturity date	Nov. 30, 2038
Uncollateralized Senior Note Due July Two Thousand Thirty Five
Debt Instrument [Line Items]
Total long-term debt	$ (50,000)	(50,000)
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Debt instrument, maturity date	Jul. 15, 2035
Uncollateralized Senior Note Due August Two Thousand Thirty Five
Debt Instrument [Line Items]
Total long-term debt	$ (40,000)	(40,000)
Debt Instrument, Interest Rate, Stated Percentage	2.96%
Debt instrument, maturity date	Aug. 15, 2035
Uncollateralized Senior Note Due November Two Thousand Thirty Nine
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Equipment Security Note
Debt Instrument [Line Items]
Total long-term debt	$ (6,957)	(7,633)
Debt Instrument, Interest Rate, Stated Percentage	2.46%
Debt instrument, maturity date	Sep. 24, 2031
Uncollateralized Senior Note Due January Two Thousand Thirty Seven
Debt Instrument [Line Items]
Total long-term debt	$ (50,000)	(50,000)
Debt Instrument, Interest Rate, Stated Percentage	2.49%
Debt instrument, maturity date	Jan. 25, 2037
Uncollateralized Senior Note Due March 15, 2042
Debt Instrument [Line Items]
Total long-term debt	$ (50,000)	(50,000)
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Debt instrument, maturity date	Mar. 15, 2042
Uncollateralized Senior Note Due March 14, 2038
Debt Instrument [Line Items]
Total long-term debt	$ (80,000)
Debt Instrument, Interest Rate, Stated Percentage	5.43%
Debt instrument, maturity date	Mar. 14, 2038
Uncollateralized Senior Note Due March 14, 2038 [Abstract]
Debt Instrument [Line Items]
Total long-term debt		(80,000)
Uncollateralized Senior Note Due December 2026
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Debt Instrument, Interest Rate, Stated Percentage	6.39%
Debt instrument, maturity date	Dec. 31, 2026
Uncollateralized Senior Note Due December 2027
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Debt Instrument, Interest Rate, Stated Percentage	6.44%
Debt instrument, maturity date	Dec. 31, 2027
Uncollateralized Senior Note Due December 2028
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Debt Instrument, Interest Rate, Stated Percentage	6.45%
Debt instrument, maturity date	Dec. 31, 2028
Uncollateralized Senior Note Due December 2030
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Debt Instrument, Interest Rate, Stated Percentage	6.62%
Debt instrument, maturity date	Dec. 31, 2030
Uncollateralized Senior Note Due December 2033
Debt Instrument [Line Items]
Total long-term debt	$ (100,000)	(100,000)
Debt Instrument, Interest Rate, Stated Percentage	6.71%
Debt instrument, maturity date	Dec. 31, 2033
Uncollateralized Senior Note Due December 2038
Debt Instrument [Line Items]
Total long-term debt	$ (50,000)	(50,000)
Debt Instrument, Interest Rate, Stated Percentage	6.73%
Debt instrument, maturity date	Dec. 31, 2038
Term Note Due January Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Total long-term debt	$ (70,000)	$ (70,000)
Prudential [Member] | Uncollateralized Senior Note Due March 14, 2038
Debt Instrument [Line Items]
Total long-term debt	$ (80,000)