Repositioning and Other Changes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Repositioning costs incurred	$ 663	$ 0	$ 6,043	$ 0
Total Amount Expected to be Incurred in the Repositioning Plan	7,418		7,418
Cumulative Amount Incurred through June 30, 2021	7,318		7,318
Severance and termination benefits
Restructuring Cost and Reserve [Line Items]
Repositioning costs incurred	76		185
Total Amount Expected to be Incurred in the Repositioning Plan	185		185
Cumulative Amount Incurred through June 30, 2021	185		185
Office space consolidation
Restructuring Cost and Reserve [Line Items]
Repositioning costs incurred	0		2,071
Total Amount Expected to be Incurred in the Repositioning Plan	2,071		2,071
Cumulative Amount Incurred through June 30, 2021	2,071		2,071
Professional services
Restructuring Cost and Reserve [Line Items]
Repositioning costs incurred	587		3,787
Total Amount Expected to be Incurred in the Repositioning Plan	5,162		5,162
Cumulative Amount Incurred through June 30, 2021	$ 5,062		$ 5,062