Summary of Significant Accounting Policies (Details 3) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended		0 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013 Available for sale securities Securities in captive insurance subsidiary portfolio Minimum	Dec. 31, 2013 Available for sale securities Securities in captive insurance subsidiary portfolio Maximum	Oct. 23, 2012 Available for sale securities Original investment de-merged into CSCG and CAPC	Oct. 23, 2012 Available for sale securities CSCG	Oct. 23, 2012 Available for sale securities CAPC	Dec. 31, 2013 Held-to-maturity securities	Dec. 31, 2012 Held-to-maturity securities
Marketable and Non-Marketable Securities
Investment maturity period			1 year	10 years
Net unrealized gains (losses) recorded in accumulated other comprehensive income (loss)	$ 2.6	$ 1.1
Number of shares owned						35,400,000	38,900,000
Proceeds received from the sale of investments					327.1
Gain recognized on sale of investment					82.7
Amount included in gain reclassified from accumulated other comprehensive income (loss)					79.4
Investments used to fund debt service requirements								0	24.9
Carrying value of investments under the cost method	98.9	118.8
Other-than-temporary non-cash charges	$ 71.0