Equity and Debt Securities

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Equity and Debt Securities

Note 3. Equity and Debt Securities

The Company’s equity and debt securities consisted of the following:

	December 31, 2022
	Amortized Cost Basis			Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
Equity securities:
Long-term
Preferred stock of privately held company	$	15,000		$	—	$	—		$	15,000
Total equity securities		15,000			—		—			15,000
Available-for-sale debt securities
Short-term
U.S. government debt securities		189,333			—		(3,373	)		185,960
Corporate debt securities		120,480			—		(2,222	)		118,258
U.S. treasury bills		69,991			—		(193	)		69,798
U.S. agency debt securities		68,411			—		(342	)		68,069
Money market accounts		27,455			—		—			27,455
Municipal bonds		7,371			—		(80	)		7,291
Yankee debt securities		2,347			—		(5	)		2,342
Less: Cash equivalents		(32,444	)		—		—			(32,444	)
Total debt securities due within 1 year		452,944			—		(6,215	)		446,729
After 1 year through 5 years
U.S. government debt securities		152,435			2		(6,349	)		146,088
U.S. agency debt securities		92,054			—		(3,435	)		88,619
Corporate debt securities		80,647			—		(4,756	)		75,891
Municipal bonds		12,065			—		(217	)		11,848
Yankee debt securities		753			—		(85	)		668
Redeemable preferred stock investment		20,000			—		(7,615	)		12,385
Total debt securities due after 1 year through 5 years		357,954			2		(22,457	)		335,499
After 5 years through 10 years
Municipal bonds		3,617			—		(83	)		3,534
Total debt securities due after 5 years through 10 years		3,617			—		(83	)		3,534
Total available-for-sale debt securities		814,515			2		(28,755	)		785,762
Total equity and debt securities	$	829,515		$	2	$	(28,755	)	$	800,762

	December 31, 2021
	Amortized Cost Basis			Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
Equity securities:
Short-term
Bond funds	$	99,314		$	—	$	(515	)	$	98,799
Exchange traded funds		35,174			—		(174	)		35,000
Total equity securities		134,488			—		(689	)		133,799
Available-for-sale debt securities
Short-term
Corporate debt securities		92,116			24		(148	)		91,992
Money market accounts		77,067			—		—			77,067
U.S. government debt securities		51,318			—		(81	)		51,237
Municipal bonds		4,980			—		(12	)		4,968
Yankee debt securities		3,615			—		(6	)		3,609
Less: Cash equivalents		(77,067	)		—		—			(77,067	)
Total debt securities due within 1 year		152,029			24		(247	)		151,806
After 1 year through 5 years
Corporate debt securities		242,421			29		(1,913	)		240,537
U.S. government debt securities		147,699			7		(786	)		146,920
U.S. agency debt securities		70,069			—		(535	)		69,534
Municipal bonds		11,920			13		(11	)		11,922
Yankee debt securities		8,633			—		(89	)		8,544
Total debt securities due after 1 year through 5 years		480,742			49		(3,334	)		477,457
After 5 years through 10 years
Municipal bonds		7,633			—		(43	)		7,590
Redeemable preferred stock investment		20,000			1,965		—			21,965
Total debt securities due after 5 years through 10 years		27,633			1,965		(43	)		29,555
Total available-for-sale debt securities		660,404			2,038		(3,624	)		658,818
Total equity and debt securities	$	794,892		$	2,038	$	(4,313	)	$	792,617

Gross unrealized losses on the Company’s equity and debt securities were $28.8 million and $4.3 million as of December 31, 2022 and 2021, respectively. The Company did not recognize any credit losses for its available-for-sale debt securities in 2022 and 2021.

The Company’s marketable securities of $472.8 million, managed by the custodian of the Company’s marketable debt security investment account, of which the Company has an outstanding margin loan, is used as collateral for the margin account borrowing. See Note 8, Debt, Commitments and Contingencies, for more information on the margin loan.