Fair Value Measurements (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended			9 Months Ended		9 Months Ended	12 Months Ended
	Jun. 14, 2013 Senior Redeemable Preferred Stock [Member]	Aug. 24, 2012 Senior Redeemable Preferred Stock [Member]	May 16, 2012 Senior Redeemable Preferred Stock [Member]	Sep. 30, 2013 Senior Redeemable Preferred Stock [Member]	Dec. 31, 2012 Senior Redeemable Preferred Stock [Member]	Sep. 30, 2013 Public Preferred Stock [Member]	Dec. 31, 2012 Public Preferred Stock [Member]	Dec. 31, 1991 Public Preferred Stock [Member]	Dec. 31, 1990 Public Preferred Stock [Member]	Sep. 30, 2012 I T Logistics Inc [Member] Subordinated Promissory Note [Member]	Sep. 30, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Public Preferred Stock [Member]	Dec. 31, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] Public Preferred Stock [Member]	Sep. 30, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Public Preferred Stock [Member]	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Public Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Face value of debt instrument										$ 15
Fair value of debt instrument										11.7
Carrying amount of debt instrument										12.5
Percentage of stock redeemed (in hundredths)	54.50%	36.00%	26.70%
Redemption price of senior preferred stock	2.0	2.0	2.0
Carrying amount of senior redeemable preferred stock				1.9	4.0
Preferred stock dividend rate per annum (in hundredths)				14.125%		12.00%	12.00%	6.00%	6.00%
Public preferred stock par value (in dollar per share)						$ 0.01
Public preferred stock											$ 115.3	$ 112.5	$ 47.8	$ 47.8