Retirement Plans (Schedule of Rollforward of Pension Plan Assets Measured at Fair Value on a Recurring Basis Using Unobservable Inputs (Level 3)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair value of plan assets at end of year	$ 281	$ 254
(Level 3)
Fair value of plan assets at beginning of year	23	17
Purchases, sales, and settlements	(1)	6
Fair value of plan assets at end of year	$ 22	$ 23