Fair Value Measurements Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]

The following table summarizes the levels of fair value measurements of our financial assets:

	March 31, 2022						December 31, 2021
(in thousands)	Total		Level 1		Level 2		Total		Level 1		Level 2
Money market funds	$	579,096	$	579,096	$	—	$	579,105	$	579,105	$	—
U.S. Treasury bills	6,856		6,856		—		5,782		5,782		—
Municipal bonds	25,754		—		25,754		26,009		—		26,009
Total	$	611,706	$	585,952	$	25,754	$	610,896	$	584,887	$	26,009

Investments Classified by Contractual Maturity Date [Table Text Block]

As of March 31, 2022, the contractual maturities of the marketable securities in our portfolio were less than one year.

Debt Securities, Available-for-sale

The following is a summary of our available-for-sale marketable securities:

(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
March 31, 2022
U.S. Treasury bills	$	6,874	$	—	$	(18)	$	6,856
Municipal bonds	25,837		—		(83)		25,754
December 31, 2021
U.S. Treasury bills	$	5,783	$	—	$	(1)	$	5,782
Municipal bonds	26,017		—		(8)		26,009