Restructuring Plans - Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		9 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Cash paid	$ (267)
Charges (reversals) to expense	604			$ 1,050			$ 3,399	$ 3,177
Restructuring reserve, ending balance	553						553
United Kingdom and Australia Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Initial reserve						$ 557
Cash paid	(2)	$ (2)	$ (6)	(649)		(54)
Restructuring reserve, beginning balance	9	11	39	503	$ 39		39
Charges (reversals) to expense			(22)	425
Restructuring reserve, ending balance	7	9	11	279	9	503	7	279
United Kingdom and Australia Restructuring Plan | Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Initial reserve						297
Cash paid	0	0	0	(400)		0
Restructuring reserve, beginning balance	0	0	1	297	1		1
Charges (reversals) to expense			(1)	132
Restructuring reserve, ending balance	0	0	0	29	0	297	0	29
United Kingdom and Australia Restructuring Plan | Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Initial reserve						127
Cash paid	0	0	0	(74)		(13)
Restructuring reserve, beginning balance	0	0	24	114	24		24
Charges (reversals) to expense			(24)	152
Restructuring reserve, ending balance	0	0	0	192	0	114	0	192
United Kingdom and Australia Restructuring Plan | Other Costs
Restructuring Cost and Reserve [Line Items]
Initial reserve						133
Cash paid	(2)	(2)	(6)	(175)		(41)
Restructuring reserve, beginning balance	9	11	14	92	14		14
Charges (reversals) to expense			3	141
Restructuring reserve, ending balance	7	9	11	58	9	$ 92	7	58
Strategic Business Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, ending balance	123			797			123	797
Strategic Business Initiative | Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Initial reserve								797
Cash paid	(100)	(196)	(212)
Restructuring reserve, beginning balance	223	422	634		634		634
Charges (reversals) to expense		(3)
Restructuring reserve, ending balance	123	223	422	$ 797	223		123	$ 797
Performance Improvement Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, ending balance	553						553
Performance Improvement Initiative | Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Cash paid		(461)	(490)
Restructuring reserve, beginning balance	820	1,586	2,076		2,076		2,076
Charges (reversals) to expense	(219)	(305)
Restructuring reserve, ending balance		820	1,586		820
Resource Alignment Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, ending balance	502						502
Resource Alignment Initiative | Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Cash paid	(308)				(20)
Restructuring reserve, beginning balance	1,029		$ 1,049		1,049		1,049
Restructuring reserve, ending balance	$ 502	$ 1,029			$ 1,029		$ 502