Business Combinations - Aggregated Consideration And Preliminary Purchase Price Allocation (Details) - Series of Individually Immaterial Business Acquisitions - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition, Contingent Consideration [Line Items]
Common Stock Issued (in shares)	207	141
Common Stock Value	$ 6,940	$ 3,543
Cash Paid	66,051	35,474
Other Payable	0	59
Recorded Contingent Consideration	38,148	16,237
Total Recorded Purchase Price	111,139	55,313
Other Assets Acquired, net	10,179	1,940
Identifiable Intangible Assets Acquired	40,753	4,807
Goodwill	60,207	48,565
Total Net Assets Acquired	111,139	55,312
Maximum Potential Contingent Consideration	$ 40,126	$ 18,736