Employee and Non Employee Director Stock and Benefit Plans (Details 2) (Stock options, USD $)	12 Months Ended
	Dec. 31, 2011 Y
Range of Exercise Prices
Number Outstanding (in shares)	526,970
Weighted Average Remaining Contractual Life (in years)	4.05
Weighted Average Exercise Price (in dollars per share)	$ 27.27
Number Exercisable (in shares)	221,344
Weighted Average Exercise Price (in dollars per share)	$ 41.18
Range of Exercise Prices $12.17 to $17.44
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)	$ 17.44
Number Outstanding (in shares)	128,348
Weighted Average Remaining Contractual Life (in years)	4.00
Weighted Average Exercise Price (in dollars per share)	$ 14.68
Number Exercisable (in shares)	22,870
Weighted Average Exercise Price (in dollars per share)	$ 16.87
Range of Exercise Prices $17.45 to $18.71
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 17.45
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 18.71
Number Outstanding (in shares)	192,733
Weighted Average Remaining Contractual Life (in years)	7.15
Weighted Average Exercise Price (in dollars per share)	$ 18.71
Range of Exercise Prices $18.72 to $45.04
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)	$ 45.04
Number Outstanding (in shares)	72,708
Weighted Average Remaining Contractual Life (in years)	1.46
Weighted Average Exercise Price (in dollars per share)	$ 35.22
Number Exercisable (in shares)	65,293
Weighted Average Exercise Price (in dollars per share)	$ 36.94
Range of Exercise Prices $45.05 to $47.25
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 45.05
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 47.25
Number Outstanding (in shares)	60,340
Weighted Average Remaining Contractual Life (in years)	1.01
Weighted Average Exercise Price (in dollars per share)	$ 47.25
Number Exercisable (in shares)	60,340
Weighted Average Exercise Price (in dollars per share)	$ 47.25
Range of Exercise Prices $47.26 to $47.59
Range of Exercise Prices
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 47.26
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 47.59
Number Outstanding (in shares)	72,841
Weighted Average Remaining Contractual Life (in years)	1.00
Weighted Average Exercise Price (in dollars per share)	$ 47.59
Number Exercisable (in shares)	72,841
Weighted Average Exercise Price (in dollars per share)	$ 47.59