Debt (Tables)

6 Months Ended

Jun. 30, 2022

Debt Disclosure [Abstract]

Schedule of Long-term Debt

The following table presents the carrying amounts and estimated fair values of our convertible senior notes that are not recorded at fair value on our consolidated balance sheets:

	June 30, 2022				December 31, 2021
Issuance	Net Carrying Amount		Estimated Fair Value		Net Carrying Amount		Estimated Fair Value
2023 notes	$	23,355	$	21,264	$	23,280	$	34,487
2025 notes	652,164		386,534		650,783		593,366
2027 notes	564,354		268,962		563,234		467,814

The following table summarizes borrowings under these facilities as of the periods presented:

	June 30, 2022
Lender	Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings		Maturity Date
City National Bank	$	100,000	$	36,151	3.63	%	10/11/2022
Comerica Bank	75,000		33,448		3.80		Upon lender demand
Origin Bank	75,000		35,000		4.31		9/30/2022
People's United Bank, National Association	50,000		21,695		3.47		10/19/2022
Prosperity Bank	150,000		81,268		3.71		9/30/2022
Republic Bank & Trust Company	75,000		31,906		3.32		8/17/2022
Wells Fargo Bank, N.A.	135,000		44,964		3.52		As determined by lender
Western Alliance Bank	25,000		13,871		3.18		12/2/2022
Total	$	685,000	$	298,303	—		—

	December 31, 2021
Lender	Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings
Western Alliance Bank	$	50,000	$	17,089	3.00	%
Texas Capital Bank, N.A.	40,000		11,852		3.01
Flagstar Bank, FSB	25,000		4,102		3.00
Total	$	115,000	$	33,043	—

The following table summarizes borrowings under this facility as of the periods presented:

	June 30, 2022						December 31, 2021
Lender	Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings		Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings
Goldman Sachs Bank USA	$	400,000	$	156,540	4.55	%	$	200,000	$	199,781	3.30	%

Convertible Debt

We have issued convertible senior notes with the following characteristics:

Issuance	Maturity Date	Stated Cash Interest Rate		Effective Interest Rate		First Interest Payment Date	Semi-Annual Interest Payment Dates	Conversion Rate
2023 notes	July 15, 2023	1.75	%	2.45	%	January 15, 2019	January 15; July 15	32.7332
2025 notes	October 15, 2025	—		0.42		—	—	13.7920
2027 notes	April 1, 2027	0.50		0.90		October 1, 2021	April 1; October 1	10.6920

The components of our convertible senior notes were as follows:

	June 30, 2022
Issuance	Aggregate Principal Amount		Unamortized Debt Discount		Unamortized Debt Issuance Costs		Net Carrying Amount
2023 notes	$	23,512	$	—	$	157	$	23,355
2025 notes	661,250		—		9,086		652,164
2027 notes	575,000		—		10,646		564,354

	December 31, 2021
Issuance	Aggregate Principal Amount		Unamortized Debt Discount		Unamortized Debt Issuance Costs		Net Carrying Amount
2023 notes	$	23,512	$	—	$	232	$	23,280
2025 notes	661,250		—		10,467		650,783
2027 notes	575,000		—		11,766		563,234

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
2023 notes
Contractual interest expense	$	103	$	104	$	206	$	208
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	38		39		75		110
Total interest expense	$	141	$	143	$	281	$	318
2025 notes
Contractual interest expense	—		—		—		—
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	690		690		1,380		1,380
Total interest expense	$	690	$	690	$	1,380	$	1,380
2027 notes
Contractual interest expense	719		715		1,438		749
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	560		557		1,120		585
Total interest expense	$	1,279	$	1,272	$	2,558	$	1,334
Total
Contractual interest expense	822		819		1,644		957
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	1,288		1,286		2,575		2,075
Total interest expense	$	2,110	$	2,105	$	4,219	$	3,032

Interest Income and Interest Expense Disclosure

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
2023 notes
Contractual interest expense	$	103	$	104	$	206	$	208
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	38		39		75		110
Total interest expense	$	141	$	143	$	281	$	318
2025 notes
Contractual interest expense	—		—		—		—
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	690		690		1,380		1,380
Total interest expense	$	690	$	690	$	1,380	$	1,380
2027 notes
Contractual interest expense	719		715		1,438		749
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	560		557		1,120		585
Total interest expense	$	1,279	$	1,272	$	2,558	$	1,334
Total
Contractual interest expense	822		819		1,644		957
Amortization of debt discount	—		—		—		—
Amortization of debt issuance costs	1,288		1,286		2,575		2,075
Total interest expense	$	2,110	$	2,105	$	4,219	$	3,032