Employee and Non-Employee Director Stock and Benefit Plans (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012
Range of Exercise Prices
Number Outstanding (in shares)	510,975
Weighted Average Remaining Contractual Life	3 years 1 month 28 days
Weighted Average Exercise Price (in dollars per share)	$ 26.77
Number Exercisable (in shares)	319,793
Weighted Average Exercise Price (in dollars per share)	$ 32.53
Range of Exercise Prices $12.17 to $18.71 | Stock options
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 12.17
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 18.71
Number Outstanding (in shares)	321,081
Weighted Average Remaining Contractual Life	4 years 10 months 20 days
Weighted Average Exercise Price (in dollars per share)	$ 17.10
Number Exercisable (in shares)	129,899
Weighted Average Exercise Price (in dollars per share)	$ 17.06
Range of Exercise Prices $18.72 to $37.51 | Stock options
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 18.72
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 37.51
Number Outstanding (in shares)	33,569
Weighted Average Remaining Contractual Life	1 year 1 month 20 days
Weighted Average Exercise Price (in dollars per share)	$ 25.97
Number Exercisable (in shares)	33,569
Weighted Average Exercise Price (in dollars per share)	$ 25.97
Range of Exercise Prices $37.52 to $47.59 | Stock options
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 37.52
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 47.59
Number Outstanding (in shares)	156,325
Weighted Average Remaining Contractual Life	14 days
Weighted Average Exercise Price (in dollars per share)	$ 46.81
Number Exercisable (in shares)	156,325
Weighted Average Exercise Price (in dollars per share)	$ 46.81