Debt (Tables)

3 Months Ended

Mar. 31, 2023

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:

	March 31, 2023				December 31, 2022
Issuance	Net Carrying Amount		Estimated Fair Value		Net Carrying Amount		Estimated Fair Value
2023 notes	$	23,468	$	22,718	$	23,431	$	22,147
2025 notes	362,617		263,998		512,683		309,292
2027 notes	566,034		354,723		565,474		267,398

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

	March 31, 2023						December 31, 2022
Lender	Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings		Borrowing Capacity		Outstanding Borrowings		Weighted-Average Interest Rate on Outstanding Borrowings
City National Bank	$	75,000	$	24,513	6.69	%	$	75,000	$	27,288	5.89	%
Comerica Bank	75,000		27,185		6.92	%	75,000		26,526		6.36	%
Origin Bank	75,000		23,997		6.54	%	75,000		23,739		5.98	%
M&T Bank	50,000		16,086		6.98	%	50,000		19,126		6.45	%
Prosperity Bank	100,000		36,043		6.67	%	100,000		35,856		6.18	%
Republic Bank & Trust Company	75,000		28,112		6.63	%	75,000		26,636		5.81	%
Wells Fargo Bank, N.A.	100,000		29,347		6.88	%	100,000		31,338		6.41	%
Total	$	550,000	$	185,283			$	550,000	$	190,509

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

We issued our 2023 notes on July 23, 2018, with an aggregate principal amount of $143,750. Subsequent to the issuance date, we repurchased or settled conversions of an aggregate of $120,238 of our 2023 notes. On July 20, 2021, our 2023 notes became redeemable by us, but we did not exercise our redemption right during the three months ended March 31, 2023.

We issued our 2025 notes on October 20, 2020, with an aggregate principal amount of $661,250. In the three months ended March 31, 2023, we repurchased and retired approximately $152,222 in aggregate principal amount of our 2025 notes at a price of $108,274 using available cash. In connection with these repurchases, we recorded a gain on extinguishment of debt of $42,270 for the three months ended March 31, 2023.

We issued our 2027 notes on March 25, 2021 and April 5, 2021, with an aggregate principal amount of $575,000.

The components of our convertible senior notes were as follows:

	March 31, 2023
Issuance	Aggregate Principal Amount		Unamortized Debt Discount		Unamortized Debt Issuance Costs		Net Carrying Amount
2023 notes	$	23,512	$	—	$	44	$	23,468
2025 notes	366,506		—		3,889		362,617
2027 notes	575,000		—		8,966		566,034

	December 31, 2022
Issuance	Aggregate Principal Amount		Unamortized Debt Discount		Unamortized Debt Issuance Costs		Net Carrying Amount
2023 notes	$	23,512	$	—	$	81	$	23,431
2025 notes	518,728		—		6,045		512,683
2027 notes	575,000		—		9,526		565,474

Interest Income and Interest Expense Disclosure

	Three Months Ended March 31,
	2023		2022
2023 notes
Contractual interest expense	$	103	$	103
Amortization of debt discount	—		—
Amortization of debt issuance costs	38		38
Total interest expense	$	141	$	141
2025 notes
Contractual interest expense	—		—
Amortization of debt discount	—		—
Amortization of debt issuance costs	2,156		690
Total interest expense	$	2,156	$	690
2027 notes
Contractual interest expense	719		719
Amortization of debt discount	—		—
Amortization of debt issuance costs	560		560
Total interest expense	$	1,279	$	1,279
Total
Contractual interest expense	822		822
Amortization of debt discount	—		—
Amortization of debt issuance costs	2,754		1,288
Total interest expense	$	3,576	$	2,110