Stock Compensation Plans (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012
Summary of information about fixed stock options
Number of Options Outstanding	6,700,825
Number of Options Exercisable	3,072,970
Exercise Price 1 [Member]
Summary of information about fixed stock options
Exercise Price	$ 12.50
Number of Options Outstanding	2,184,542
Weighted-Average Remaining Contractual Life	9 years
Number of Options Exercisable	728,181
Exercise Price 2 [Member]
Summary of information about fixed stock options
Exercise Price	$ 14.00
Number of Options Outstanding	1,710,683
Weighted-Average Remaining Contractual Life	3 years
Number of Options Exercisable	1,133,789
Exercise Price 3 [Member]
Summary of information about fixed stock options
Exercise Price	$ 14.50
Number of Options Outstanding	1,593,600
Weighted-Average Remaining Contractual Life	10 years
Exercise Price 4 [Member]
Summary of information about fixed stock options
Exercise Price	$ 15.00
Number of Options Outstanding	3,000
Weighted-Average Remaining Contractual Life	3 years
Number of Options Exercisable	2,000
Exercise Price 5 [Member]
Summary of information about fixed stock options
Exercise Price	$ 17.50
Number of Options Outstanding	1,198,500
Weighted-Average Remaining Contractual Life	6 months
Number of Options Exercisable	1,198,500
Exercise Price 6 [Member]
Summary of information about fixed stock options
Exercise Price	$ 18.70
Number of Options Outstanding	3,000
Weighted-Average Remaining Contractual Life	6 months
Number of Options Exercisable	3,000
Exercise Price 7 [Member]
Summary of information about fixed stock options
Exercise Price	$ 21.00
Number of Options Outstanding	7,500
Weighted-Average Remaining Contractual Life	6 months
Number of Options Exercisable	7,500