Earnings Per Share

6 Months Ended

Jun. 30, 2012

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 and six months ended June 30, 2012 and 2011:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands, except per share data)	2012		2011		2012		2011
Net earnings	$	81,016	$	105,166	$	114,914	$	52,669
Less: net earnings allocable to participating securities	399		1,012		556		544
Net earnings available for common shareholders	$	80,617	$	104,154	$	114,358	$	52,125
Basic net earnings per share	$	1.47	$	1.93	$	2.08	$	0.97
Diluted net earnings per share	$	1.46	$	1.90	$	2.07	$	0.95
Weighted average shares outstanding—basic	54,942		54,004		54,851		53,936
Add: Dilutive effects of stock options and RSUs	352		704		451		755
Weighted average shares outstanding—dilutive	55,294		54,708		55,302		54,691

0.7 million and 0.3 million stock options and RSUs were not included in the diluted earnings per share calculation for the three and six months ended June 30, 2012, respectively, because their effect would have been anti-dilutive. There were no stock options or RSUs excluded from the diluted earnings per share calculation for the three and six months ended June 30, 2011.