Stock-Based Compensation (Details) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Number of common shares reserved for issuance
Shares available for granting under the 2002 plan (in shares)	26.8		19.2
Options outstanding (in shares)	18.6		27.0
Total shares reserved for issuance (in shares)	45.4	[1]	46.2	[1]
Director Deferred Stock Ownership Plan [Member]
Number of common shares reserved for issuance
Total shares reserved for issuance (in shares)	0.2		0.2

[1] Shares reserved for issuance under the Director Deferred Stock Ownership Plan are included in the total, but are less than 0.2 million.