Convertible Debt (Tables)

6 Months Ended

Jun. 30, 2021

0 Percent Convertible Senior Notes [Member]

Convertible Notes [Abstract]

Convertible Notes

At June 30, 2021, we had the following 0% Notes outstanding (amounts in millions except interest rate and price per share data):

	0% Notes
Outstanding principal balance	$	632.5
Unamortized debt issuance costs	$	15.1
Maturity date	April 2026
Interest rate	0 percent
Effective interest rate	0.5 percent
Conversion price per share	$	57.84
Effective conversion price per share with call spread	$	76.39
Total shares of common stock subject to conversion		10.9

0.125 Percent Convertible Senior Notes [Member]

Convertible Notes [Abstract]

Convertible Notes

At June 30, 2021, we had the following 0.125% Notes outstanding with interest payable semi-annually (amounts in millions except interest rate and price per share data):

	0.125% Notes
Outstanding principal balance	$	548.8
Unamortized debt issuance costs	$	7.6
Maturity date	December 2024
Interest rate	0.125 percent
Effective interest rate	0.5 percent
Conversion price per share	$	83.28
Effective conversion price per share with call spread	$	123.38
Total shares of common stock subject to conversion		6.6

1 Percent Convertible Senior Notes [Member]

Convertible Notes [Abstract]

Convertible Notes

At June 30, 2021, we had the following 1% Notes outstanding with interest payable semi-annually (amounts in millions except interest rate and price per share data):

	1% Notes
Outstanding principal balance	$62.0
Unamortized debt issuance costs	$0.1
Maturity date	November 2021
Interest rate	1 percent
Effective interest rate	1.4 percent
Conversion price per share	$66.81
Total shares of common stock subject to conversion	0.9