Earnings Per Share

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Earnings Per Share

Earnings Per Share

Basic net earnings per share is calculated by dividing net earnings available to common shareholders by the weighted average shares outstanding-basic during each period. Diluted earnings per share is calculated by dividing earnings available to common shareholders by the weighted average shares outstanding-dilutive, which includes the effect of potentially dilutive securities. Potentially dilutive securities consist of unvested restricted stock awards and outstanding stock options. No potential shares of common stock are included in the computation of any diluted per share amount when a net loss exists.

The two-class method of computing net earnings per share is required for those entities that have participating securities. The two-class method is an earnings allocation formula that determines net earnings per share for participating securities according to dividends declared (or accumulated) and participation rights in undistributed earnings. Unvested restricted shares issued under the Company's equity incentive plans prior to January 1, 2010 have the right to receive non-forfeitable dividends, participating on an equal basis with common shares, and thus are classified as participating securities. Participating securities do not have a contractual obligation to share in the Company's losses. Therefore, in periods of net loss, no portion of the loss is allocated to participating securities. Unvested restricted shares issued subsequent to January 1, 2010 under the Company's equity incentive plans do not participate in dividends. Stock options issued under the Company's equity incentive plans do not participate in dividends.

The following table shows the computation of basic and diluted net earnings per share for the three months ended March 31, 2013 and 2012:

	Three Months Ended
	March 31,
(in thousands, except per share data)	2013		2012
Net earnings	$	32,434	$	33,898
Less: net earnings allocable to participating securities	81		171
Net earnings available for common shareholders	$	32,353	$	33,727
Basic net earnings per share	$	0.59	$	0.62
Diluted net earnings per share	$	0.58	$	0.61
Basic weighted average shares outstanding	55,186		54,759
Add: Dilutive effects of stock options and RSUs	379		504
Dilutive weighted average shares outstanding	55,565		55,263

Not included in the diluted earnings per share calculation were 0.8 million and 0.3 million stock options and RSUs, for the three months ended March 31, 2013 and March 31, 2012, respectively, because their effect would have been anti-dilutive.