Net Income Per Share

12 Months Ended

Dec. 31, 2012

Net Income Per Share [Abstract]

Net Income Per Share

11.           Net Income Per Share

We utilize the two-class method to compute net income per share.  The two-class method allocates a portion of net income to participating securities, which include unvested awards of share-based payments with non-forfeitable rights to receive dividends.  Net income allocated to unvested share-based payments is excluded from net income allocated to common shares.  Any undistributed losses resulting from dividends exceeding net income are not allocated to participating securities.  Basic net income per share is computed by dividing net income allocated to common shares by the weighted average number of common shares outstanding during the period.  Diluted net income per share is computed by dividing net income allocated to common shares by the weighted average number of common shares outstanding during the period, plus the dilutive effect of outstanding stock options.

The following table summarizes the net income allocated to common shares and the basic and diluted shares used in the net income per share computations:

	Year ended December 31,
	2012			2011			2010
	(in thousands)
Net income	$	40,402		$	30,470		$	22,440
Less distributed and undistributed earnings allocated to participating securities		(1,224	)		(908	)		(657	)
Net income allocated to common shares	$	39,178		$	29,562		$	21,783
Weighted average common shares outstanding		25,007			25,405			25,254
Incremental shares from assumed conversions of common stock options		60			92			114
Adjusted weighted average common shares outstanding		25,067			25,497			25,368
Potentially dilutive securities not included in weighted average share calculation due to anti-dilutive effect		29			29			372