Business Combinations - Changes in Contingent Purchase Price Consideration (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Combinations [Abstract]
Net Expense (Income)	$ 846	$ 74	$ 1,599	$ (80)
Cash Settlement Paid	$ 0	$ 4,995	$ 7,584	$ 10,881
Shares Issued (number)	13,000	0	66,000	81,000