Employee Benefit Plans - Schedule of Estimated Future Benefit Payments (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Chesapeake Pension Plan
Defined Benefit Plan, Expected Future Benefit Payments, Maturity [Line Items]
2017	$ 528	[1]
2018	529	[1]
2019	736	[1]
2020	595	[1]
2021	1,244	[1]
Years 2022 through 2026	3,866	[1]
FPU Pension Plan
Defined Benefit Plan, Expected Future Benefit Payments, Maturity [Line Items]
2017	3,091	[1]
2018	3,221	[1]
2019	3,299	[1]
2020	3,485	[1]
2021	3,558	[1]
Years 2022 through 2026	18,570	[1]
Chesapeake SERP
Defined Benefit Plan, Expected Future Benefit Payments, Maturity [Line Items]
2017	383	[2]
2018	150	[2]
2019	148	[2]
2020	147	[2]
2021	145	[2]
Years 2022 through 2026	744	[2]
Chesapeake Postretirement Plan
Defined Benefit Plan, Expected Future Benefit Payments, Maturity [Line Items]
2017	96	[2]
2018	85	[2]
2019	82	[2]
2020	81	[2]
2021	64	[2]
Years 2022 through 2026	275	[2]
FPU Medical Plan
Defined Benefit Plan, Expected Future Benefit Payments, Maturity [Line Items]
2017	94	[2]
2018	87	[2]
2019	91	[2]
2020	93	[2]
2021	80	[2]
Years 2022 through 2026	$ 402	[2]

[1] The pension plan is funded; therefore, benefit payments are expected to be paid out of the plan assets.

[2] Benefit payments are expected to be paid out of our general funds.