Allowance For Credit Losses - Activities In Allowance For Credit Losses (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 3,469
Additions (reductions)	(213)	$ 2,387
Write-offs	(1,846)
Balance at end of period	$ 1,410	3,172
Cumulative Effect, Period of Adoption | Accounting Standards Update 2016-13
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year		785
Robotics
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Additions (reductions)		$ 1,700