Stock Plans and Management Compensation (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Range 01 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 3.37
Exercise price range, upper range limit (in dollars per share)	$ 5.99
Number of outstanding options (in shares)	2,204
Outstanding options, weighted average remaining years of contractual life (in years)	6 years 1 month 6 days
Outstanding options, weighted average exercise price (in dollars per share)	$ 5.11
Number of options exercisable (in shares)	1,586
Exercisable options, weighted average remaining years of contractual life (in years)	6 years 2 months 12 days
Exercisable options, weighted average exercise price (in dollars per share)	$ 5.02
Range 02 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 6.00
Exercise price range, upper range limit (in dollars per share)	$ 19.90
Number of outstanding options (in shares)	3,146
Outstanding options, weighted average remaining years of contractual life (in years)	6 years 3 months 18 days
Outstanding options, weighted average exercise price (in dollars per share)	$ 13.59
Number of options exercisable (in shares)	2,093
Exercisable options, weighted average remaining years of contractual life (in years)	5 years 10 months 24 days
Exercisable options, weighted average exercise price (in dollars per share)	$ 14.64
Range 03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 19.91
Exercise price range, upper range limit (in dollars per share)	$ 39.56
Number of outstanding options (in shares)	2,446
Outstanding options, weighted average remaining years of contractual life (in years)	5 years 7 months 6 days
Outstanding options, weighted average exercise price (in dollars per share)	$ 28.82
Number of options exercisable (in shares)	1,440
Exercisable options, weighted average remaining years of contractual life (in years)	3 years 7 months 6 days
Exercisable options, weighted average exercise price (in dollars per share)	$ 33.36
Range 04 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 39.57
Exercise price range, upper range limit (in dollars per share)	$ 46.25
Number of outstanding options (in shares)	370
Outstanding options, weighted average remaining years of contractual life (in years)	1 year 8 months 12 days
Outstanding options, weighted average exercise price (in dollars per share)	$ 46.02
Number of options exercisable (in shares)	370
Exercisable options, weighted average remaining years of contractual life (in years)	1 year 8 months 12 days
Exercisable options, weighted average exercise price (in dollars per share)	$ 46.02