Leases (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2021 lease	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right of use assets (Note 10)		$ 1,957		$ 614
Operating Lease, Liability		6,672		$ 12,900
Number of leases abandoned | lease	14
Restricted cash in prepaid expenses and other current assets		1,480	$ 0
Gain on settlement of leases		3,483	$ 0
Israel
Lessee, Lease, Description [Line Items]
Restricted cash in prepaid expenses and other current assets		1,300
Australia
Lessee, Lease, Description [Line Items]
Restricted cash in prepaid expenses and other current assets		$ 200
Minimum
Leases [Abstract]
Operating leases remaining lease term		1 year
Lessee, Lease, Description [Line Items]
Operating leases remaining lease term		1 year
Maximum
Leases [Abstract]
Operating leases remaining lease term		5 years
Lessee, Lease, Description [Line Items]
Operating leases remaining lease term		5 years