| Schedule of long-term debt instruments |
The components of long-term debt were as follows as of March 31, 2024 (in thousands, except percentages): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Long-term Debt | | Effective Interest Rate | | Principal Amount | | Unamortized Debt Discount and Issuance Costs | | Net Carrying Amount | | | | | 0.50% 2026 Convertible Notes due on June 1, 2026 | | 0.98 | % | | $ | 1,273,013 | | | $ | (13,890) | | | $ | 1,259,123 | | | | | | 3.38% 2028 Senior Notes due on October 1, 2028 | | 3.57 | % | | 1,000,000 | | | (7,810) | | | 992,190 | | | | | | 0.25% 2030 Convertible Notes due on April 1, 2030 | | 0.55 | % | | 1,265,000 | | | (22,038) | | | 1,242,962 | | | | | | 3.63% 2031 Senior Notes due on October 1, 2031 | | 3.77 | % | | 737,457 | | | (6,718) | | | 730,739 | | | | | | | Total | | | | $ | 4,275,470 | | | $ | (50,456) | | | $ | 4,225,014 | | | | | |
The components of long-term debt were as follows as of December 31, 2023 (in thousands, except percentages): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Long-term Debt | | Effective Interest Rate | | Principal Amount | | Unamortized Debt Discount and Issuance Costs | | Net Carrying Amount | | | | | 0.50% 2026 Convertible Notes due on June 1, 2026 | | 0.98 | % | | $ | 1,273,013 | | | $ | (15,378) | | | $ | 1,257,635 | | | | | | 3.38% 2028 Senior Notes due on October 1, 2028 | | 3.57 | % | | 1,000,000 | | | (8,218) | | | 991,782 | | | | | | 3.63% 2031 Senior Notes due on October 1, 2031 | | 3.77 | % | | 737,457 | | | (6,917) | | | 730,540 | | | | | | | Total | | | | $ | 3,010,470 | | | $ | (30,513) | | | $ | 2,979,957 | | | | | |
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