Stock-Based Compensation (Details 2) (Stock options, USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Options Outstanding
Number Outstanding (in shares)	1,064
Weighted Average Remaining Contractual Life	7 years 9 months 29 days
Weighted Average Exercise Price (in dollars per share)	$ 33.37
Options Exercisable
Number Exercisable (in shares)	360
Weighted Average Exercise Price (in dollars per share)	$ 30.91
$17.30 - $29.05
Information about options outstanding
Low end of exercise price range (in dollars per share)	$ 17.30
High end of exercise price range (in dollars per share)	$ 29.05
Options Outstanding
Number Outstanding (in shares)	322
Weighted Average Remaining Contractual Life	7 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 28.21
Options Exercisable
Number Exercisable (in shares)	120
Weighted Average Exercise Price (in dollars per share)	$ 27.44
$29.35 - $33.65
Information about options outstanding
Low end of exercise price range (in dollars per share)	$ 29.35
High end of exercise price range (in dollars per share)	$ 33.65
Options Outstanding
Number Outstanding (in shares)	282
Weighted Average Remaining Contractual Life	6 years 4 days
Weighted Average Exercise Price (in dollars per share)	$ 32.61
Options Exercisable
Number Exercisable (in shares)	205
Weighted Average Exercise Price (in dollars per share)	$ 32.22
$35.20 - $35.70
Information about options outstanding
Low end of exercise price range (in dollars per share)	$ 35.20
High end of exercise price range (in dollars per share)	$ 35.70
Options Outstanding
Number Outstanding (in shares)	46
Weighted Average Remaining Contractual Life	5 years 3 months 22 days
Weighted Average Exercise Price (in dollars per share)	$ 35.36
Options Exercisable
Number Exercisable (in shares)	35
Weighted Average Exercise Price (in dollars per share)	$ 35.25
$37.41 - $40.17
Information about options outstanding
Low end of exercise price range (in dollars per share)	$ 37.41
High end of exercise price range (in dollars per share)	$ 40.17
Options Outstanding
Number Outstanding (in shares)	414
Weighted Average Remaining Contractual Life	9 years 7 months 10 days
Weighted Average Exercise Price (in dollars per share)	$ 37.67