Pension Benefits, Other Postretirement Benefits and Employee Savings and Investment Plans (Additional Information) (Detail)	2 Months Ended		3 Months Ended		7 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Jun. 01, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) plan	Dec. 31, 2018 USD ($)	Jul. 27, 2020 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of qualified noncontributory defined benefit plans | plan							2
Merged plan assets	$ 12,790,000	$ 12,790,000	$ 12,790,000			$ 5,278,000	$ 12,790,000
PBO of plan assets for pension plan with plan assets in excess of its PBO	30,000,000.0	30,000,000.0	30,000,000.0			30,000,000.0	30,000,000.0
ABO of plan assets for pension plan with plan assets in excess of its PBO	30,000,000.0	30,000,000.0	30,000,000.0			30,000,000.0	30,000,000.0
Fair value of the plan assets for pension plan with plan assets in excess of its PBO	42,800,000	42,800,000	42,800,000			35,300,000	42,800,000
PBO of plan assets for pension plan with plan assets in excess of its ABO	30,000,000.0	30,000,000.0	30,000,000.0			30,000,000.0	30,000,000.0
ABO of plan assets for pension plan with plan assets in excess of its ABO	30,000,000.0	30,000,000.0	30,000,000.0			30,000,000.0	30,000,000.0
Fair value of the plan assets for pension plan with plan assets in excess of its ABO	$ 42,800,000	$ 42,800,000	$ 42,800,000			$ 35,300,000	$ 42,800,000
Health care cost, employees age						65 years	65 years
Health care cost trend rate annual change (as a percentage)						0.25%
Retirees of 65 Years Old or Younger
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Health care cost trend rate assumed for next fiscal year (as a percentage)	6.75%	6.75%	6.75%			6.50%	6.75%
Ultimate health care cost trend rate (as a percentage)						4.50%
Retirees of 65 Years Old or Older
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Health care cost trend rate assumed for next fiscal year (as a percentage)	6.75%	6.75%	6.75%			6.50%	6.75%
Ultimate health care cost trend rate (as a percentage)						4.50%
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annuity payments						$ (237,000)	$ 162,484,000
Merged plan assets	$ 12,790,000	$ 12,790,000	$ 12,790,000			5,278,000	12,790,000
Plan assets	$ 42,835,000	$ 42,835,000	$ 42,835,000			$ 35,296,000	42,835,000	$ 191,652,000
Expected long-term rate of return on plan assets (as a percentage)						4.53%
Employer contributions						$ 0	$ 41,000
Pension Benefits | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocations (as a percentage)	92.00%	92.00%	92.00%			90.00%	92.00%
Pension Benefits | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan asset allocations (as a percentage)	8.00%	8.00%	8.00%			10.00%	8.00%
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annuity payments						$ 0	$ 0
Merged plan assets	$ 0	$ 0	$ 0			0	0
Plan assets	0	0	0			0	0	0
PBO of plan assets for other postretirement benefit plans with ABO in excess of plan assets	1,600,000	1,600,000	1,600,000			1,500,000	1,600,000
ABO of plan assets for other postretirement benefit plans with ABO in excess of plan assets	(1,600,000)	(1,600,000)	(1,600,000)			(1,500,000)	(1,600,000)
Employer contributions						192,000	273,000
Merged Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions							25,000,000.0
Merged Plan | Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annuity payments	$ 1,300,000				$ 123,300,000
Lump sum distributions		$ 38,900,000
Non-cash pre-tax settlement charge in connection with termination of Merged Plan			$ 53,200,000	$ 0
Merged plan assets						9,100,000
Rogers Employee Savings and Investment Plan (RESIP)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions						4,900,000	$ 4,400,000	$ 5,600,000
IRS deferral limit						$ 19,000
Rogers Employee Savings and Investment Plan (RESIP) | 100% match
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee compensation subject to employer matching percent (as a percentage)						3.50%
Rogers Employee Savings and Investment Plan (RESIP) | 100% match | 1% of compensation
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee compensation subject to employer matching percent (as a percentage)						100.00%
Employer matching contribution (as a percentage)						1.00%
Rogers Employee Savings and Investment Plan (RESIP) | 50% match | 5% of compensation
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee compensation subject to employer matching percent (as a percentage)						5.00%
Employer matching contribution (as a percentage)						50.00%
Rogers Employee Savings and Investment Plan (RESIP) | Suspense Account Held Within a Trust
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets									$ 7,400,000