Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2020

Summary of Investments Measured at Fair Value on Recurring Basis

The following table summarizes the Company’s investments at March 31, 2020 and December 31, 2019 measured at fair value on a recurring basis (in thousands):

	March 31, 2020							December 31, 2019
			Gross							Gross
			Unrealized							Unrealized
			Gains			Recorded				Gains			Recorded
	Cost		(Losses)			Basis		Cost		(Losses)			Basis
Current:
Cash equivalents:
Money market funds	$	2,135	$	—		$	2,135	$	35,526	$	—		$	35,526
Total cash equivalents		2,135		—			2,135		35,526		—			35,526
Investments:
Corporate bonds		36,937		(783	)		36,154		53,493		156			53,649
Asset backed securities		36,989		(4,434	)		32,555		14,017		(13	)		14,004
U.S. government agency securities		7,405		424			7,829		7,408		282			7,690
U.S. treasuries		2,448		17			2,465		4,500		9			4,509
Mortgage backed securities		361		9			370		2,737		1			2,738
Total investments		84,140		(4,767	)		79,373		82,155		435			82,590
Restricted cash and investments ⁽¹⁾:
Corporate bonds		99,452		1,629			101,081		98,481		1,931			100,412
Mortgage backed securities		59,961		1,978			61,939		62,930		837			63,767
Money market funds		34,418		(23	)		34,395		29,046		—			29,046
U.S. government agency securities		25,739		1,166			26,905		27,885		642			28,527
U.S. treasuries		7,271		63			7,334		16,906		21			16,927
Supranational bonds		4,771		71			4,842		4,770		30			4,800
Mutual funds		3,514		—			3,514		3,466		—			3,466
Asset backed securities		291		(2	)		289		303		—			303
Total restricted cash and investments		235,417		4,882			240,299		243,787		3,461			247,248
Total investments	$	321,692	$	115		$	321,807	$	361,468	$	3,896		$	365,364

(1) Included in restricted cash and investments within the condensed consolidated balance sheet is restricted cash of $226.4 million and $197.0 million as of March 31, 2020 and December 31, 2019, respectively, which is excluded from the table above. Restricted cash and investments are classified as current and noncurrent on the balance sheet based on the nature of the restriction.

Summary of Assets Measured at Fair Value on Recurring Basis

The following table summarizes the Company’s investments at March 31, 2020 and December 31, 2019 measured at fair value on a recurring basis by fair value hierarchy level (in thousands):

	March 31, 2020										December 31, 2019
	Total										Total
	Recorded										Recorded
	Basis		Level 1		Level 2		Level 3		Other ⁽¹⁾		Basis		Level 1		Level 2		Level 3		Other ⁽¹⁾
Cash equivalents:
Money market funds	$	2,135	$	—	$	—	$	—	$	2,135	$	35,526	$	—	$	—	$	—	$	35,526
Investments:
Corporate bonds		36,154		—		36,154		—		—		53,649		—		53,649		—		—
Asset backed securities		32,555		—		32,555		—		—		14,004		—		14,004		—		—
U.S. government agency securities		7,829		—		7,829		—		—		7,690		—		7,690		—		—
U.S. treasuries		2,465		—		2,465		—		—		4,509		—		4,509		—		—
Mortgage backed securities		370		—		370		—		—		2,738		—		2,738		—		—
Restricted cash and investments:
Corporate bonds		101,081		—		101,081		—		—		100,412		—		100,412		—		—
Mortgage backed securities		61,939		—		61,939		—		—		63,767		—		63,767		—		—
Money market funds		34,395		—		—		—		34,395		29,046		—		—		—		29,046
U.S. government agency securities		26,905		—		26,905		—		—		28,527		—		28,527		—		—
U.S. treasuries		7,334		—		7,334		—		—		16,927		—		16,927		—		—
Supranational bonds		4,842		—		4,842		—		—		4,800		—		4,800		—		—
Mutual funds		3,514		3,514		—				—		3,466		3,466		—				—
Asset backed securities		289		—		289		—		—		303		—		303		—		—
Total investments	$	321,807	$	3,514	$	281,763	$	—	$	36,530	$	365,364	$	3,466	$	297,326	$	—	$	64,572

(1) Investments in money market funds measured at fair value using the net asset value per share practical expedient are not subject to hierarchy level classification disclosure. The Company invests in money market funds that seek to maintain a stable net asset value. These investments include commingled funds that comprise high-quality short-term securities representing liquid debt and monetary instruments where the redemption value is likely to be the fair value. Redemption is permitted daily without written notice.

Summary of Contractual Maturities of Available for Sale Securities

The following table summarizes the contractual maturities of the Company’s available-for-sale securities at March 31, 2020. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.

	March 31, 2020
(In thousands)	Less than 1 Year		Between 1 to 5 Years		Between 5 to 10 Years		After 10 Years		Total
Corporate bonds	$	16,277	$	81,828	$	25,001	$	14,129	$	137,235
Money market funds		36,530		—		—		—		36,530
U.S. government agency securities		—		6,505		28,229		—		34,734
Asset backed securities		—		303		—		32,541		32,844
U.S. treasuries		8,569		1,230		—		—		9,799
Supranational bonds		4,842		—		—		—		4,842
Total	$	66,218	$	89,866	$	53,230	$	46,670	$	255,984

	December 31, 2019
(In thousands)	Less than 1 Year		Between 1 to 5 Years		Between 5 to 10 Years		After 10 Years		Total
Corporate bonds	$	7,238	$	120,887	$	25,936	$	—	$	154,061
Money market funds		64,572		—		—		—		64,572
U.S. government agency securities		2,128		6,425		27,664		—		36,217
U.S. treasuries		20,632		804		—		—		21,436
Asset backed securities		—		319		—		13,988		14,307
Supranational bonds		—		4,800		—		—		4,800
Total	$	94,570	$	133,235	$	53,600	$	13,988	$	295,393