Share-Based Payments (General Descriptions) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended						3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Common Class A [Member]	Dec. 31, 2013 Common Class A [Member]	Jun. 20, 2008 Common Class A [Member]	Jun. 25, 2004 Common Class A [Member]	Mar. 31, 2014 Director [Member]	Mar. 31, 2014 Employees [Member]	Jun. 25, 2004 1995 Plan [Member] Common Class A [Member]	Jun. 20, 2008 2008 Plan [Member] Common Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value			$ 1	$ 1	$ 1.00	$ 1.00
Share-based payments, number of shares authorized under plans									300,000	300,000
Annual vesting percentage							20.00%	20.00%
Requisite service period of awards							1 year	3 years
Expiration period of awards	10 years
Period in force, from which option holders may elect to sell back acquired shares	90 days
Pre-tax compensation cost (benefit) recognized	$ 1.7	$ 1.5
Compensation cost (benefit), tax expense (benefit)	0.6	0.5
Compensation cost related to nonvested options not yet recognized	$ 3.4
Weighted average period over which the compensation is expected to be recognized	2 years 6 months