The calculations of earnings per common share for the quarters and nine-month periods ended September 30, 2020 and 2019 are as follows:

Quarter Ended

Nine-Month Period Ended

September 30,

2020

2019

2020

2019

(In thousands, except per share information)

Net income

$

28,613

$

46,327

$

52,135

$

130,928

Less: Preferred stock dividends

(669)

(2,007)

Net income attributable to common stockholders

$

27,944

$

45,658

$

50,128

$

128,921

Weighted-Average Shares:

Average common shares outstanding

216,922

216,690

216,876

216,569

Average potential dilutive common shares

793

537

657

484

Average common shares outstanding - assuming dilution

217,715

217,227

217,533

217,053

Earnings per common share:

Basic

$

0.13

$

0.21

$

0.23

$

0.60

Diluted

$

0.13

$

0.21

$

0.23

$

0.59