Restructuring Charges Restructuring Liability Rollforward (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 1,016	$ 159
Restructuring and Related Cost, Incurred Cost	1,600
Payments for Restructuring	(741)
Restructuring Reserve, Accrual Adjustment	(2)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	7	68
Restructuring and Related Cost, Incurred Cost	412
Payments for Restructuring	(477)
Restructuring Reserve, Accrual Adjustment	4
Office Space Reductions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	85	91
Restructuring and Related Cost, Incurred Cost	0
Payments for Restructuring	0
Restructuring Reserve, Accrual Adjustment	(6)
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	924	$ 0
Restructuring and Related Cost, Incurred Cost	1,188
Payments for Restructuring	(264)
Restructuring Reserve, Accrual Adjustment	$ 0