Restructuring (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended	24 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred	$ 21,000	$ (300,000)	$ 10,439,000	$ 6,879,000
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020			5,957,000
Costs incurred			4,237,000
Cash disbursements			(9,952,000)
Non-cash charges			(11,000)
Balance as of September 30, 2020	231,000		231,000		$ 231,000	$ 231,000
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			10,400,000		20,600,000
Impairment on right-of-use asset			6,200,000
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		$ (300,000)	0	$ 6,700,000		19,000,000.0
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020			5,707,000
Costs incurred			4,180,000
Cash disbursements			(9,645,000)
Non-cash charges			0
Balance as of September 30, 2020	242,000		242,000		242,000	242,000
Software Charges
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020			99,000
Costs incurred			0
Cash disbursements			(99,000)
Non-cash charges			0
Balance as of September 30, 2020	0		0		0	0
Other
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020			151,000
Costs incurred			57,000
Cash disbursements			(208,000)
Non-cash charges			(11,000)
Balance as of September 30, 2020	$ (11,000)		$ (11,000)		$ (11,000)	$ (11,000)