The following table reconciles the number of shares used in calculating basic and diluted earnings per share:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands, except per share amounts)	2019		2018		2019		2018
Net income	$	20,565	$	60,336	$	44,262	$	121,081

Basic weighted-average shares outstanding		67,446		62,986		67,781		58,765
Incremental shares due to:
Performance shares		65		270		50		263
Restricted stock units		34		37		17		33
Stock portion of earnings and profits distribution		—		1,429		—		481
Diluted weighted-average shares outstanding		67,545		64,722		67,848		59,542

Basic net income per share	$	0.30	$	0.96	$	0.65	$	2.06
Diluted net income per share	$	0.30	$	0.93	$	0.65	$	2.03

For stock-based awards, the dilutive effect is calculated using the treasury stock method. Under this method, the dilutive effect is computed as if the awards were exercised at the beginning of the period (or at time of issuance, if later) and assumes the related proceeds were used to repurchase common stock at the average market price during the period. Related proceeds include future compensation cost associated with the stock award.

For the three and nine months ended September 30, 2019, there were approximately 25,000 and 134,000 stock-based awards that were excluded from the calculation of diluted earnings per share because they were anti-dilutive. For the three and nine months ended September 30, 2018, there were approximately 16,000 and 38,000 stock-based awards that were excluded from the calculation of diluted earnings per share because they were anti-dilutive. Anti-dilutive stock-based awards could be dilutive in future periods.

In February 2018 we issued 22.0 million shares in connection with the Deltic merger. Further, on August 30, 2018, the board of directors approved a special distribution of $222.0 million, or approximately $3.54 per share. The special distribution amount equaled our determination of the accumulated earnings and profits of Deltic as of the merger date and was distributed in order to maintain the company’s qualification as a REIT for U.S. federal income tax purposes. The special distribution was paid on November 15, 2018, to stockholders of record on September 27, 2018 through the issuance of 4.8 million shares of our common stock and distribution of $44.4 million in cash. The weighted average shares for the dilutive effect on earnings per share from the stock portion of the special distribution was based on the August 30, 2018 declaration date for the three and nine months ended September 30, 2018. See Note 3: Merger with Deltic for further discussion on the merger.

On August 30, 2018, our board of directors authorized management to repurchase up to $100.0 million of common stock with no time limit set for the repurchase (the 2018 Repurchase Program). We repurchased 0.7 million shares of common stock (at a total consideration of $25.2 million) during the six months ended June 30, 2019, and we repurchased no shares during the three months ended September 30, 2019 under the 2018 Repurchase Program. All common stock purchases under the 2018 Repurchase Programs were made in open-market transactions. No shares were repurchased during the three and nine months ended September 30, 2018. At September 30, 2019, we had remaining authorization of $74.8 million for future stock repurchases under the 2018 Repurchase Program.

We record share repurchases upon trade date as opposed to the settlement date when cash is disbursed. We record a liability to account for repurchases that have not been cash settled. There were no unsettled repurchases as of September 30, 2019. We retire shares upon repurchase. Any excess repurchase price over par is recorded in accumulated deficit.