Restructuring Charges and Asset Impairments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve
Balance at	$ 12,006,000	$ 15,449,000
Expenses, net	18,071,000	23,705,000
Cash payments	(20,014,000)	(27,148,000)	$ (52,730,000)
Balance at	10,063,000	12,006,000	15,449,000
Asset impairment charges	0	44,000,000	1,000,000
Restructuring charges and asset impairments	20,712,000	69,606,000	25,899,000
Non cash charges	$ 3,000,000	2,000,000
Minimum
Restructuring Reserve
Restructuring reserve, payment period	12 months
Maximum
Restructuring Reserve
Restructuring reserve, payment period	24 months
Severance and benefits costs
Restructuring Reserve
Balance at	$ 11,937,000	13,641,000
Expenses, net	16,399,000	22,794,000
Cash payments	(18,295,000)	(24,498,000)
Balance at	10,041,000	11,937,000	13,641,000
Other exit costs
Restructuring Reserve
Balance at	69,000	1,808,000
Expenses, net	1,672,000	911,000
Cash payments	(1,719,000)	(2,650,000)
Balance at	$ 22,000	$ 69,000	$ 1,808,000