Components of Net Periodic Benefit Cost (Narrative) (Detail) - USD ($)			3 Months Ended	12 Months Ended
	Mar. 31, 2022	Jan. 01, 2007	Mar. 31, 2022	Dec. 31, 2002
Retirement Benefits [Abstract]
Service period for employees of coverage age, years (at least)			1 year
Defined benefit plan, percentage vested	100.00%		100.00%
Retiree benefits eliminated if less than service period, years (less than)		10 years		10 years
Defined benefit plan, contributions by employer	$ 0