Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Company recognized pretax costs	$ 2,600,000	$ 3,500,000	$ 700,000
Accrued liability, included in other noncurrent liabilities	$ 43,200,000	43,800,000
Pension Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage required for corridor approach	10.00%
Pension Benefit Plan [Member] | Other Expense, Net [Member] | Upon Termination of Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial gains (losses)			34,500,000
Pension Benefit Plan [Member] | U.S.Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's defined benefit pension plans	$ 13,500,000	12,800,000
Defined benefit pension plan assets	0	0
Company expects to contribute to defined benefit pension plans	800,000
Pension and other postretirement benefit liabilities	12,700	12,000.0
Pretax gains recognized in accumulated other comprehensive loss	(2,300,000)	(1,300,000)
Net periodic benefit cost	400,000	300,000	34,000,000.0
Pension Benefit Plan [Member] | Non-U.S.Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's defined benefit pension plans	261,800,000	211,800,000
Defined benefit pension plan assets	279,100,000	230,800,000	203,400,000
Company expects to contribute to defined benefit pension plans	6,700,000
Pension and other postretirement benefit liabilities	34,400	23,200
Pretax gains recognized in accumulated other comprehensive loss	(43,900,000)	(32,200,000)
Net periodic benefit cost	4,100,000	4,000,000.0	2,900,000
Other Postretirement Benefit Plans [Member] | Other Expense, Net [Member] | Upon Termination of Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial gains (losses) and prior service credits			9,700,000
Other Postretirement Benefit Plans [Member] | U.S.Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit liabilities	4,500,000	3,900,000
Pretax gains recognized in accumulated other comprehensive loss	4,500,000	2,300,000
Net periodic benefit cost	1,300,000	1,000,000.0	7,400,000
CommScope, Inc. Retirement Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's contribution to defined contribution retirement savings plans	$ 56,600,000	$ 41,800,000	$ 24,000,000.0