Note 12 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value Measurements Using
September 30, 2021	Fair Value		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	112,462	$	112,462	$	–	$	–
Restricted cash and cash equivalents		14,305		14,305		–		–
Marketable equity securities		130,413		130,413		–		–
Corporate debt securities		87,691		45,640		42,051		–
Mortgage–backed securities		36,968		-		36,968		–
U.S. Treasury securities		39,965		39,965		–		–
State and municipal securities		9,497		-		9,497		–
Total financial assets	$	431,301	$	342,785	$	88,516	$	–

	Fair Value Measurements Using
December 31, 2020	Fair Value		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	147,093	$	147,093	$	–	$	–
Restricted cash and cash equivalents		11,409		11,409		–		–
Marketable equity securities		133,270		133,270		–		–
Corporate debt securities		92,025		56,772		35,253		–
Asset–backed securities		44,249		–		44,249		–
U.S. Treasury securities		40,663		40,663		–		–
State and municipal securities		12,898		–		12,898		–
Total financial assets	$	481,607	$	389,207	$	92,400	$	–