Stock-Based Compensation (Details 2) (2012 Amended Executive Officer Non-Qualified Stock Option Agreement, USD $)	12 Months Ended
	Dec. 31, 2012
$14.13 to $18.82
Stock options outstanding and exercisable
Exercise Price Range, Lower Range Limit (in dollars per share)	$ 14.13
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 18.22
OPTIONS OUTSTANDING
NUMBER OUTSTANDING (in shares)	1,638,376
WEIGHTED-AVERAGE REMAINING LIFE	4 years 2 months 12 days
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 16.96
OPTIONS EXERCISABLE
NUMBER EXERCISABLE (in shares)	417,067
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 15.24
$20.99 to $37.37
Stock options outstanding and exercisable
Exercise Price Range, Lower Range Limit (in dollars per share)	$ 20.99
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 37.37
OPTIONS OUTSTANDING
NUMBER OUTSTANDING (in shares)	1,012,603
WEIGHTED-AVERAGE REMAINING LIFE	1 year 7 months 6 days
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 25.66
OPTIONS EXERCISABLE
NUMBER EXERCISABLE (in shares)	782,275
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 26.18
$40.00 to $72.13
Stock options outstanding and exercisable
Exercise Price Range, Lower Range Limit (in dollars per share)	$ 40.00
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 72.13
OPTIONS OUTSTANDING
NUMBER OUTSTANDING (in shares)	768,444
WEIGHTED-AVERAGE REMAINING LIFE	1 year 7 months 6 days
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 49.84
OPTIONS EXERCISABLE
NUMBER EXERCISABLE (in shares)	768,444
WEIGHTED-AVERAGE EXERCISE PRICE (in dollars per share)	$ 49.84