Derivative Instruments and Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2018

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Impact of Derivative Instruments on Consolidated Statements of Income and Accumulated OCI

The impact of derivative instruments on the consolidated statements of income and accumulated OCI was as follows (dollars in millions):

	Net Loss Recognized in Accumulated OCI (Effective Portion) December 31,
	2018			2017
Treasury locks, net of tax	$	(10.2	)	$	(14.2	)

	Loss Reclassified from Accumulated OCI into Income (Effective Portion) Year Ended December 31,
	2018			2017			2016
Amortization of treasury locks (included in interest    expense, net and other)	$	(5.3	)	$	(5.7	)	$	(5.7	)