Restructuring and Other Related Charges (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges	$ 8,625	$ 5,966
Restructuring charges	8,625
Accrued restructuring costs	7,400
Management Changes
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges	8,600
A M C N I Reporting Unit | Management Changes
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,500
Severance and employee-related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,168
Severance and employee-related costs | Management Changes
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,100