Fair Value (Items Measured At Fair Value On A Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Total
Cash equivalents:
Derivative assets (see Note T)	$ 4.0	$ 1.2
Total assets	198.7	193.0
Liabilities:
Derivative liabilities (see Note T)	0.9	4.7
Total liabilities	41.5	38.4
Total | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the ESUP (see Note M)	41.0	32.7
Total | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP (see Note M)	40.6	33.7
Level 1
Cash equivalents:
Derivative assets (see Note T)	0.0	0.0
Total assets	41.0	32.7
Liabilities:
Derivative liabilities (see Note T)	0.0	0.0
Total liabilities	40.6	33.7
Level 1 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the ESUP (see Note M)	41.0	32.7
Level 1 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP (see Note M)	40.6	33.7
Level 2
Cash equivalents:
Derivative assets (see Note T)	4.0	1.2
Total assets	157.7	160.3
Liabilities:
Derivative liabilities (see Note T)	0.9	4.7
Total liabilities	0.9	4.7
Level 2 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the ESUP (see Note M)	0.0	0.0
Level 2 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP (see Note M)	0.0	0.0
Level 3
Cash equivalents:
Derivative assets (see Note T)	0.0	0.0
Total assets	0.0	0.0
Liabilities:
Derivative liabilities (see Note T)	0.0	0.0
Total liabilities	0.0	0.0
Level 3 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the ESUP (see Note M)	0.0	0.0
Level 3 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP (see Note M)	0.0	0.0
Bank time deposits with original maturities of three months or less | Total
Cash equivalents:
Bank time deposits with original maturities of three months or less	153.7	159.1
Bank time deposits with original maturities of three months or less | Level 1
Cash equivalents:
Bank time deposits with original maturities of three months or less	0.0	0.0
Bank time deposits with original maturities of three months or less | Level 2
Cash equivalents:
Bank time deposits with original maturities of three months or less	153.7	159.1
Bank time deposits with original maturities of three months or less | Level 3
Cash equivalents:
Bank time deposits with original maturities of three months or less	$ 0.0	$ 0.0