Accumulated Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
ACCUMULATED COMPREHENSIVE LOSS [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	$ 0.6	$ (7.8)	$ 7.7
Foreign currency translation adjustments, beginning of period	(8.2)	(0.4)	(8.1)
Pension adjustments, beginning of period	(96.0)	(73.2)	(65.6)
Unrealized gain (loss) on derivative instruments, beginning of period	0.4	(0.3)	(0.1)
Unreazlied gain (loss) on investments, beginning of period	0.2	6.5	11.4
Other, beginning of period	(2.6)	(2.2)	(2.2)
Accumulated comprehensive loss, net of tax, beginning of period	(107.9)	(106.2)	(69.6)	(64.6)
Pension adjustments, activity	(3.0)	(22.8)	(7.6)
Unrealized gain (loss) on derivative financial instruments, activity	(0.7)	0.7	(0.2)
Unrealized gain (loss) on investments, activity	0.8	(6.3)	(4.9)
Other, activity	0.6	(0.4)	0
Other comprehensive income (loss), activity	(1.7)	(36.6)	(5.0)
Foreign currency translation adjustments, end of period	(7.6)	(8.2)	(0.4)
Pension adjustments, end of period	(99.0)	(96.0)	(73.2)
Unrealized gain (loss) on derivative instruments, end of period	(0.3)	0.4	(0.3)
Unreazlied gain (loss) on investments, end of period	1.0	0.2	6.5
Other, end of period	(2.0)	(2.6)	(2.2)
Accumulated comprehensive loss, net of tax, end of period	(107.9)	(106.2)	(69.6)	(64.6)
Pension adjustments income tax benefit	$ 0.9	$ 14.1	$ 3.0