Acquisition (Schedule Of Pro Forma Information) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Acquisition [Abstract]
Total revenues	$ 140,604	$ 116,520
Net income	$ 24,849	$ 20,021
Basic net income per share	$ 0.45	$ 0.42
Diluted net income per share	$ 0.43	$ 0.41