Schedule I Schedule I - CONDENSED STATEMENT OF CASH FLOWS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	$ 26.5	$ 60.3	$ 104.4
Cash flows from investing activities
Payments to acquire businesses, net of transaction costs and cash acquired	(37.9)	(19.0)	(30.6)
Purchase of additional interest in subsidiary	0	(75.4)	(19.5)
Other	(5.5)	(9.9)	14.4
Cash flows used in investing activities	(1,224.9)	(1,006.3)	(278.5)
Cash flows from financing activities
Issuance of common stock, net of fees	17.4	0	0
Other	(18.8)	(17.0)	(23.3)
Transfer to affiliates	0	0	0
Cash flows provided by financing activities	1,472.6	811.5	187.4
Net increase/(decrease) in cash and cash equivalents	857.6	(82.4)	70.3
Cash and cash equivalents, beginning of period	891.2	971.1	902.1
Cash and cash equivalents, end of period	1,757.5	891.2	971.1
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	258.6	182.9	753.9
Cash flows from investing activities
Payments to acquire businesses, net of transaction costs and cash acquired	0	(123.5)	0
Purchase of additional interest in subsidiary	(232.5)	0	0
Other	(0.8)	0	0
Cash flows used in investing activities	(233.3)	(123.5)	0
Cash flows from financing activities
Issuance of common stock, net of fees	17.4	0	0
Other	0	(1.7)	(1.6)
Transfer to affiliates	(39.2)	(189.8)	(739.0)
Cash flows provided by financing activities	(21.8)	(191.5)	(740.6)
Net increase/(decrease) in cash and cash equivalents	3.5	(132.1)	13.3
Cash and cash equivalents, beginning of period	3.9	136.0	122.7
Cash and cash equivalents, end of period	$ 7.4	$ 3.9	$ 136.0