Redeemable Noncontrolling Interests - Table 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Altoona and Jonesboro [Member]	Sep. 30, 2013 Altoona and Jonesboro [Member]	Dec. 31, 2012 Altoona [Member]
Redeemable Noncontrolling Interest [Line Items]
Balance at beginning of period			$ 13.5		$ 13.5		$ 7.2
Net Income attributable to noncontrolling interest	1.8	1.5	5.4	4.1	5.4	4.1
Distributions declared			(33.7)	(30.1)	(6.7)	(3.6)
Contribution to joint venture					0	6.2
Balance at end of period	$ 12.2		$ 12.2		$ 12.2	$ 13.9	$ 7.2