Income Tax Matters, NOL (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 736.9
NOL carryforwards related to the excess tax benefits from vesting of employee restricted stock	1.7
AMT credit carryforwards	29.1
Increase (Decrease) in valuation allowance	$ 1.2	$ (0.1)	$ (1.3)