Accumulated Other Comprehensive (Loss) Income, Net of Tax (Schedule of Accumulated Other Comprehensive Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	$ (54,812)	$ (33,991)	$ (21,212)	$ (64,202)
Net of tax	(1,062)	(1,564)	(2,130)	(3,105)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(762)	(823)	(1,531)	(1,621)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of accumualted comprehensive income
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Hedge terminations	(76)	(77)	(153)	(153)
Premium amortization	(969)	(1,037)	(1,947)	(2,042)
Income tax expense	283	291	569	574
Net of tax	(762)	(823)	(1,531)	(1,621)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Actuarial loss amortization	(411)	(1,007)	(822)	(2,015)
Defined benefit pension and postretirement benefit plans
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(300)	(741)	(599)	(1,484)
Income tax expense	$ 111	$ 266	$ 223	$ 531