On November 14, 2017, the Company issued $570.0 million senior notes due on November 15, 2024 (the “2024 Notes”). The 2024 Notes were issued at face value and bear interest at the rate of 1.50% per annum, payable semi-annually in cash on each May 15 and November 15, commencing on May 15, 2018. The 2024 Notes contain customary covenants and events of default, occurrence of which permits the certain holders to accelerate all outstanding obligations, including principal and interest. The Company incurred $10.6 million of offering costs, which represents the total debt discount on the 2024 Notes at issuance. The debt discount is amortized under the effective interest method and recorded as additional interest expense over the life of the 2024 Notes.

Upon conversion, the Company may pay cash, shares of its common stock or a combination of cash and stock, as determined by the Company in its discretion. The 2024 Notes may be convertible into 7,763,552 shares of the Company’s common stock under certain circumstances prior to maturity at a conversion rate of 13.621 shares per $1,000 principal amount of the 2024 Notes, which represents a conversion price of $73.42 per share, subject to adjustment under certain conditions. For more information related to the 2024 Notes, please read Note 13, Indebtedness of the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Upon adoption of ASU 2020-06, the 2024 Notes are accounted for as a single liability measured at its amortized cost. The cumulative effect of the accounting change as of January 1, 2021 increased the carrying amount of the convertible notes by $96.8 million, reduced the accumulated deficit by $60.2 million and reduced additional paid-in capital by $157.0 million. Interest expense of the 2024 convertible notes will be lower as a result of adoption of this guidance. The effective interest rate on the liability component of the 2024 Notes for the three months ended March 31, 2021 was 1.9%. For the three months ended March 31, 2021 and 2020, the interest expense related to the 2024 Notes was $2.7 million and $7.7 million, respectively. The fair value of the Company’s 2024 Notes as of March 31, 2021 was $735.0 million, based on open market trades and is classified as level 1 in the fair value hierarchy.

There have been no material changes to the December 2019 Term Loan in the three months ended March 31, 2021. For more information related to the term loan, please read Note 13, Indebtedness of the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

The following table summarizes the Company’s debt facilities for the periods indicated:

	As of March 31, 2021			As of December 31, 2020
	(in thousands)
Principal amount of the 2024 Notes	$	569,993		$	569,993
Unamortized discount - equity component		—			(98,721	)
Unamortized discount - debt issuance costs		(7,913	)		(6,510	)
Net carrying value of 2024 Notes		562,080			464,762
Principal amount of the 2019 Term Loan		550,000			550,000
Unamortized discounts		(20,970	)		(22,269	)
Net carrying value of 2019 Term Loan		529,030			527,731
Total carrying value of debt facilities	$	1,091,110		$	992,493

The following table summarizes the total gross payments due under the Company’s debt arrangements:

	As of March 31, 2021 (in thousands)
2021 (April-December)	$	—
2022		—
2023		250,000
2024		869,993
2025		—
Thereafter		—
Total payments	$	1,119,993