Employee Benefit Plans - Schedule of Funded Status of Benefit Obligation and Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in benefit obligation:
Interest cost	$ 0.1	$ 0.1	$ 0.1
FPU Pension Plan
Change in benefit obligation:
Benefit obligation - beginning of year	45.5	49.7
Interest cost	2.4	2.4	2.5
Actuarial loss	0.6	(2.0)
Benefits paid	(3.5)	(4.6)
Benefit obligation - end of year	45.0	45.5	49.7
Change in plan assets:
Balance, beginning of year	49.1	49.5
Actual return on plan assets	4.4	4.2
Employer contributions	0.0	0.0
Benefits paid	(3.5)	(4.6)
Balance, end of year	50.0	49.1	$ 49.5
Reconciliation:
Accrued pension cost	$ 5.0	$ 3.6
Assumptions:
Discount rate	5.25%	5.50%
Expected return on plan assets	5.50%	6.00%	6.00%
Chesapeake SERP
Change in benefit obligation:
Benefit obligation - beginning of year	$ 1.5	$ 1.6
Interest cost	0.1	0.1
Actuarial loss	(0.1)	0.0
Benefits paid	(0.2)	(0.2)
Benefit obligation - end of year	1.3	1.5	$ 1.6
Change in plan assets:
Employer contributions	0.2	0.2
Benefits paid	(0.2)	(0.2)
Reconciliation:
Accrued pension cost	$ (1.3)	$ (1.5)
Assumptions:
Discount rate	4.98%	5.40%