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)	2020		2019		2020		2019
Net income	$	81,007	$	20,565	$	66,813	$	44,262

Basic weighted-average shares outstanding		67,149		67,446		67,263		67,781
Incremental shares due to:
Performance shares		320		65		238		50
Restricted stock units		59		34		34		17
Diluted weighted-average shares outstanding		67,528		67,545		67,535		67,848

Basic net income per share	$	1.21	$	0.30	$	0.99	$	0.65
Diluted net income per share	$	1.20	$	0.30	$	0.99	$	0.65

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, 2020, there were 0 and approximately 47,000 stock-based awards, respectively, 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, 2019, there were approximately 25,000 and 134,000 stock-based awards, respectively, 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.

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). In September 2020 we entered into a trading plan in accordance with the guidelines in Rule 10b5-1 of the Securities Exchange Act of 1934, as amended, with an independent broker for the purpose of repurchasing a limited number of the Company’s common shares under the 2018 Repurchase Program. This trading plan became effective on October 29, 2020 and expires upon expenditure of the principal specified in the plan, an early termination event (as specified in the plan), or the close of business on October 26, 2022, whichever occurs first.

During the nine months ended September 30, 2020 we repurchased 489,850 shares of common stock (at a total consideration of $15.4 million), and we repurchased no shares during the three months ended September 30, 2020, under the 2018 Repurchase Program. During the nine months ended September 30, 2019 we repurchased 686,240 shares of common stock (at a total consideration of $25.2 million), 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 Program were made in open-market transactions. At September 30, 2020, we had remaining authorization of $59.5 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, 2020. We retire shares upon repurchase. Any excess repurchase price over par is recorded in accumulated deficit.