Debt (Tables)

3 Months Ended

Mar. 31, 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:

	March 31, 2022				December 31, 2021
Issuance	Net Carrying Amount		Estimated Fair Value		Net Carrying Amount		Estimated Fair Value
2023 notes	$	23,318	$	27,559	$	23,280	$	34,487
2025 notes	651,474		493,907		650,783		593,366
2027 notes	563,793		389,304		563,234		467,814

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

	March 31, 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
Western Alliance Bank	$	50,000	$	11,284	3.02	%	$	50,000	$	17,089	3.00	%
Texas Capital Bank, N.A.	40,000		8,604		3.79	%	40,000		11,852		3.01	%
Flagstar Bank, FSB	25,000		2,397		3.15	%	25,000		4,102		3.00	%
Total	$	115,000	$	22,285	—		$	115,000	$	33,043	—

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

	March 31, 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	$	136,869	3.38	%	$	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

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, 2022. For more than 20 trading days during the 30 consecutive trading days ended March 31, 2022, the volume weighted average price of our common stock was less than 130% of the conversion price of our 2023 notes. As a result, our 2023 notes will not be convertible at the option of the holders during the quarter ending June 30, 2022, and have been reclassified from current liabilities to non-current liabilities on our consolidated balance sheets as of March 31, 2022.

We issued our 2025 notes on October 20, 2020, with an aggregate principal amount of $661,250.

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, 2022
Issuance	Aggregate Principal Amount		Unamortized Debt Discount		Unamortized Debt Issuance Costs		Net Carrying Amount
2023 notes	$	23,512	$	—	$	194	$	23,318
2025 notes	661,250		—		9,776		651,474
2027 notes	575,000		—		11,207		563,793

	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

Interest Income and Interest Expense Disclosure

	Three Months Ended March 31,
	2022		2021
2023 notes
Contractual interest expense	$	103	$	104
Amortization of debt discount	—		—
Amortization of debt issuance costs	38		72
Total interest expense	$	141	$	176
2025 notes
Contractual interest expense	—		—
Amortization of debt discount	—		—
Amortization of debt issuance costs	690		690
Total interest expense	$	690	$	690
2027 notes
Contractual interest expense	719		35
Amortization of debt discount	—		—
Amortization of debt issuance costs	560		27
Total interest expense	$	1,279	$	62
Total
Contractual interest expense	822		139
Amortization of debt discount	—		—
Amortization of debt issuance costs	1,288		789
Total interest expense	$	2,110	$	928