Outstanding debt as of December 31, 2017 consisted of the following (in thousands):



December 31, 2017	Outstanding Principal Amount		Unamortized Debt Discount and Debt Issuance Cost			Carrying Value
Short-term debt:
1.0% Convertible Senior Notes due March 2018	$	714,304	$	(3,394	)	$	710,910
Long-term debt:
0.35% Convertible Senior Notes due June 2020	$	1,000,000	$	(64,825	)	$	935,175
0.9% Convertible Senior Notes due September 2021	1,000,000		(83,272		)	916,728
0.8% (€1 Billion) Senior Notes due March 2022	1,200,800		(6,238		)	1,194,562
2.15% (€750 Million) Senior Notes due November 2022	900,600		(4,683		)	895,917
2.75% Senior Notes due March 2023	500,000		(3,203		)	496,797
2.375% (€1 Billion) Senior Notes due September 2024	1,200,800		(12,240		)	1,188,560
3.65% Senior Notes due March 2025	500,000		(3,290		)	496,710
3.6% Senior Notes due June 2026	1,000,000		(6,840		)	993,160
1.8% (€1 Billion) Senior Notes due March 2027	1,200,800		(5,136		)	1,195,664
3.55% Senior Notes due March 2028	500,000		(3,485		)	496,515
Total long-term debt	$	9,003,000	$	(193,212	)	$	8,809,788

Outstanding debt as of December 31, 2016 consisted of the following (in thousands):



December 31, 2016	Outstanding Principal Amount		Unamortized Debt Discount and Debt Issuance Cost			Carrying Value
Short-term debt:
1.0% Convertible Senior Notes due March 2018	$	1,000,000	$	(32,266	)	$	967,734
Long-term debt:
0.35% Convertible Senior Notes due June 2020	$	1,000,000	$	(90,251	)	$	909,749
0.9% Convertible Senior Notes due September 2021	1,000,000		(104,592		)	895,408
2.15% (€750 Million) Senior Notes due November 2022	791,063		(5,336		)	785,727
2.375% (€1 Billion) Senior Notes due September 2024	1,054,750		(12,861		)	1,041,889
3.65% Senior Notes due March 2025	500,000		(3,727		)	496,273
3.6% Senior Notes due June 2026	1,000,000		(7,619		)	992,381
1.8% (€1 Billion) Senior Notes due March 2027	1,054,750		(5,655		)	1,049,095
Total long-term debt	$	6,400,563	$	(230,041	)	$	6,170,522