Stock Transactions and Stock-Based Compensation (Summary of Options Outstanding) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
$15.23 to $23.56
Options, Exercise Price, lower range limit	$ 15.23
Options, Exercise Price, upper range limit	$ 23.56
Outstanding, Shares	910
Outstanding, Average Exercise Price	$ 19.93
Outstanding, Average Remaining Life, in years	1 year
Exercisable, Shares	904
Exercisable, Average Exercise Price	$ 19.94
$23.57 to $31.26
Options, Exercise Price, lower range limit	$ 23.57
Options, Exercise Price, upper range limit	$ 31.26
Outstanding, Shares	8,167
Outstanding, Average Exercise Price	$ 28.40
Outstanding, Average Remaining Life, in years	4 years
Exercisable, Shares	6,080
Exercisable, Average Exercise Price	$ 28.65
$31.27 to $38.81
Options, Exercise Price, lower range limit	$ 31.27
Options, Exercise Price, upper range limit	$ 38.81
Outstanding, Shares	8,183
Outstanding, Average Exercise Price	$ 36.44
Outstanding, Average Remaining Life, in years	5 years
Exercisable, Shares	5,323
Exercisable, Average Exercise Price	$ 35.83
$38.82 to $46.81
Options, Exercise Price, lower range limit	$ 38.82
Options, Exercise Price, upper range limit	$ 46.81
Outstanding, Shares	2,539
Outstanding, Average Exercise Price	$ 40.32
Outstanding, Average Remaining Life, in years	6 years
Exercisable, Shares	1,878
Exercisable, Average Exercise Price	$ 40.17
$46.82 to $55.07
Options, Exercise Price, lower range limit	$ 46.82
Options, Exercise Price, upper range limit	$ 55.07
Outstanding, Shares	7,573
Outstanding, Average Exercise Price	$ 51.23
Outstanding, Average Remaining Life, in years	9 years
Exercisable, Shares	488
Exercisable, Average Exercise Price	$ 50.23