Fair Value and Equity Investments, Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contingent Consideration [Member]
Changes in Fair Value of Level 3 Contingent Consideration [Roll Forward]
Beginning balance	$ (3,125)	$ 0
Additions from acquisitions	(8,702)	(3,125)
Changes in fair value of contingent consideration	1,486	0
Ending balance	(10,341)	(3,125)
Fair Value on a Recurring Basis [Member]
Financial Assets (Liabilities) [Abstract]
Cash equivalents and current investments	66,477	56,628
Derivative financial instruments asset	6,590	1,145
Life insurance contracts	49,851	45,453
Derivative financial instruments liability		(105)
Contingent consideration	(10,341)	(3,125)
Financial assets (liabilities)	112,577	99,996
Restricted current investments	5,200	21,200
Fair Value on a Recurring Basis [Member] | Level 1 [Member]
Financial Assets (Liabilities) [Abstract]
Cash equivalents and current investments	66,477	56,628
Derivative financial instruments asset	0	0
Life insurance contracts	0	0
Derivative financial instruments liability		0
Contingent consideration	0	0
Financial assets (liabilities)	66,477	56,628
Fair Value on a Recurring Basis [Member] | Level 2 [Member]
Financial Assets (Liabilities) [Abstract]
Cash equivalents and current investments	0	0
Derivative financial instruments asset	6,590	1,145
Life insurance contracts	0	0
Derivative financial instruments liability		(105)
Contingent consideration	0	0
Financial assets (liabilities)	6,590	1,040
Fair Value on a Recurring Basis [Member] | Level 3 [Member]
Financial Assets (Liabilities) [Abstract]
Cash equivalents and current investments	0	0
Derivative financial instruments asset	0	0
Life insurance contracts	49,851	45,453
Derivative financial instruments liability		0
Contingent consideration	(10,341)	(3,125)
Financial assets (liabilities)	39,510	42,328
Life Insurance Contracts [Member]
Changes in Fair Value of Level 3 Marketable Securities [Roll Forward]
Beginning balance	45,453	41,707
Actual return on plan assets	5,153	3,746
Purchases and issuances	6,261	0
Sales and settlements	(7,016)	0
Transfers into Level 3	0	0
Ending balance	$ 49,851	$ 45,453