Stock Option Plans and Share-Based Compensation Stock option rollforward YTD (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Number of Shares [Roll Forward]
Beginning balance	4,693	4,740	4,748
Granted	645	494	666
Exercised	(669)	(413)	(431)
Expired	(84)	(86)	(164)
Forfeited	(115)	(42)	(79)
Ending balance	4,470	4,693	4,740
Weighted Average Exercise Price [Roll Forward]
Beginning balance	$ 13.36	$ 12.86	$ 12.61
Granted	$ 14.85	$ 14.57	$ 12.99
Exercised	$ 8.65	$ 8.30	$ 8.46
Expired	$ 14.02	$ 13.59	$ 16.50
Forfeited	$ 21.44	$ 20.76	$ 14.80
Ending balance	$ 14.06	$ 13.36	$ 12.86
Additional Disclosures [Abstract]
Vested and expected to vest	4,439
Exercisable	3,331
Vested and expected to vest	$ 14.06
Exercisable	$ 13.98
Options outstanding, weighted average remaining contractual term	5 years 3 months 18 days
Options outstanding, intrinsic value	$ 10,400,000
Vested and expected to vest, weighted average remaining contratual term	5 years 3 months 18 days
Options vested and expected to vest, aggregate intrinsic value	10,400,000
Options exercisable, weighted average remaining contractual term	4 years 2 months 12 days
Options exercisable, intrinsic value	9,300,000
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	4,470	4,693	4,740
Weighted Average Exercise Price of Outstanding Options	$ 14.06	$ 13.36	$ 12.86
Number Exercisable	3,331
Weighted Average Exercise Price of Exercisable Options	$ 13.98
Exercise price range, lower range limit	$ 2.70
Exercise price range, upper range limit	$ 29.16
Grants in period, weighted average grant date fair value	$ 6.13	$ 6.47	$ 6.13
Exercises in period, total intrinsic value	2,800,000	2,900,000	2,100,000
Vested in period, fair value	3,000,000	4,000,000	4,900,000
$2.70 - $9.25 [Member]
Number of Shares [Roll Forward]
Ending balance	518
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 7.46
Additional Disclosures [Abstract]
Exercisable	508
Exercisable	$ 7.45
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	518
Weighted Average Exercise Price of Outstanding Options	$ 7.46
Number Exercisable	508
Weighted Average Exercise Price of Exercisable Options	$ 7.45
Exercise price range, lower range limit	$ 2.70
Exercise price range, upper range limit	$ 9.25
$9.34 - $10.58 [Member]
Number of Shares [Roll Forward]
Ending balance	587
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 10.32
Additional Disclosures [Abstract]
Exercisable	579
Exercisable	$ 10.33
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	587
Weighted Average Exercise Price of Outstanding Options	$ 10.32
Number Exercisable	579
Weighted Average Exercise Price of Exercisable Options	$ 10.33
Exercise price range, lower range limit	$ 9.34
Exercise price range, upper range limit	$ 10.58
$10.60 - $11.58 [Member]
Number of Shares [Roll Forward]
Ending balance	476
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 11.05
Additional Disclosures [Abstract]
Exercisable	461
Exercisable	$ 11.06
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	476
Weighted Average Exercise Price of Outstanding Options	$ 11.05
Number Exercisable	461
Weighted Average Exercise Price of Exercisable Options	$ 11.06
Exercise price range, lower range limit	$ 10.60
Exercise price range, upper range limit	$ 11.58
$11.66 - $13.16 [Member]
Number of Shares [Roll Forward]
Ending balance	518
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 12.61
Additional Disclosures [Abstract]
Exercisable	413
Exercisable	$ 12.63
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	518
Weighted Average Exercise Price of Outstanding Options	$ 12.61
Number Exercisable	413
Weighted Average Exercise Price of Exercisable Options	$ 12.63
Exercise price range, lower range limit	$ 11.66
Exercise price range, upper range limit	$ 13.16
$13.33 - $13.74 [Member]
Number of Shares [Roll Forward]
Ending balance	455
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 13.63
Additional Disclosures [Abstract]
Exercisable	103
Exercisable	$ 13.50
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	455
Weighted Average Exercise Price of Outstanding Options	$ 13.63
Number Exercisable	103
Weighted Average Exercise Price of Exercisable Options	$ 13.50
Exercise price range, lower range limit	$ 13.33
Exercise price range, upper range limit	$ 13.74
$13.88 - $14.38 [Member]
Number of Shares [Roll Forward]
Ending balance	453
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 14.18
Additional Disclosures [Abstract]
Exercisable	168
Exercisable	$ 14.14
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	453
Weighted Average Exercise Price of Outstanding Options	$ 14.18
Number Exercisable	168
Weighted Average Exercise Price of Exercisable Options	$ 14.14
Exercise price range, lower range limit	$ 13.88
Exercise price range, upper range limit	$ 14.38
$14.42 - $16.70 [Member]
Number of Shares [Roll Forward]
Ending balance	495
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 15.66
Additional Disclosures [Abstract]
Exercisable	157
Exercisable	$ 15.22
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	495
Weighted Average Exercise Price of Outstanding Options	$ 15.66
Number Exercisable	157
Weighted Average Exercise Price of Exercisable Options	$ 15.22
Exercise price range, lower range limit	$ 14.42
Exercise price range, upper range limit	$ 16.70
$16.73 - $20.95 [Member]
Number of Shares [Roll Forward]
Ending balance	608
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 19.76
Additional Disclosures [Abstract]
Exercisable	582
Exercisable	$ 19.90
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	608
Weighted Average Exercise Price of Outstanding Options	$ 19.76
Number Exercisable	582
Weighted Average Exercise Price of Exercisable Options	$ 19.90
Exercise price range, lower range limit	$ 16.73
Exercise price range, upper range limit	$ 20.95
$21.07 - $26.99 [Member]
Number of Shares [Roll Forward]
Ending balance	280
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 22.88
Additional Disclosures [Abstract]
Exercisable	280
Exercisable	$ 22.88
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	280
Weighted Average Exercise Price of Outstanding Options	$ 22.88
Number Exercisable	280
Weighted Average Exercise Price of Exercisable Options	$ 22.88
Exercise price range, lower range limit	$ 21.07
Exercise price range, upper range limit	$ 26.99
$29.16 - $29.16 [Member]
Number of Shares [Roll Forward]
Ending balance	80
Weighted Average Exercise Price [Roll Forward]
Ending balance	$ 29.16
Additional Disclosures [Abstract]
Exercisable	80
Exercisable	$ 29.16
Share-based Compensation, Exercise Price Range [Abstract]
Number Outstanding	80
Weighted Average Exercise Price of Outstanding Options	$ 29.16
Number Exercisable	80
Weighted Average Exercise Price of Exercisable Options	$ 29.16
Exercise price range, lower range limit	$ 29.16
Exercise price range, upper range limit	$ 29.16
Stock Options [Member]
Share-based Compensation, Exercise Price Range [Abstract]
Total compensation cost not yet recognized	$ 6,600,000.00
Period for recognition	2 years 9 months 18 days