Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

The fair value and carrying value of our fixed-rate debt, excluding any unamortized debt issuance costs, are as follows:

	December 31,
(In millions)	2018		2017
Senior unsecured notes
Carrying value	$	600.0	600.0
Fair value	519.9		590.6