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

	Three Months Ended March 31,
(in thousands, except per share amounts)	2019		2018
Net income	$	6,560	$	14,597

Basic weighted-average shares outstanding		67,860		50,425
Incremental shares due to:
Performance shares		36		328
Restricted stock units		20		33
Diluted weighted-average shares outstanding		67,916		50,786

Basic net income per share	$	0.10	$	0.29
Diluted net income per share	$	0.10	$	0.29

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 months ended March 31, 2019 and 2018, there were approximately 90,000 and 64,000 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 4,814,673 shares of our common stock and distribution of $44.4 million in cash. 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). During the three months ended March 31, 2019, we repurchased 278,947 shares of common stock for $10.2 million, under the 2018 Repurchase Program. All common stock purchases under the 2018 Repurchase Programs were made in open-market transactions. At March 31, 2019, we had remaining authorization of $89.9 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 March 31, 2019. We retire shares upon repurchase. Any excess repurchase price over par is recorded in accumulated deficit.