Stock Option Activity (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Additional Disclosures
Outstanding at December 31, 2012, Weighted-average remaining contractual term	4 years 0 months 14 days
Options exercisable at December 31, 2012, Weighted-average remaining contractual term	4 years 0 months 14 days
Outstanding at December 31, 2012, Intrinsic value (in millions)	$ 0
Options exercisable at December 31, 2012, Intrinsic value (in millions)	$ 0
Stock Options
Number of Shares
Outstanding at beginning of year (in shares)	52,819
Granted (in shares)	0
Exercised (in shares)	0
Forfeited and expired (in shares)	(17,195)
Outstanding at end of year (in shares)	35,624
Options exercisable at year-end (in shares)	11,875
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 48.87
Granted (in dollars per share)	$ 0.00
Exercised (in dollars per share)	$ 0.00
Forfeited and expired (in dollars per share)	$ 48.87
Outstanding at end of year (in dollars per share)	$ 48.87
Options exercisable at year-end (in dollars per share)	$ 48.87