Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate, Continuing Operations	38.70%	39.20%	37.60%	39.30%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	$ 0	$ 0	$ (5,719)	$ 0