Earnings Per Share

The Company calculates basic earnings per common share by dividing net income attributable to the Company's common stockholders for the period by weighted-average shares of common stock outstanding for that period. Diluted earnings per common share takes into account the effect of dilutive instruments, such as convertible notes and performance share awards, and the number of incremental shares that are to be added to the weighted-average number of shares outstanding.

During the year ended December 31, 2017, the Company's Convertible Notes were determined to be dilutive and were included in the calculation of diluted earnings per common share under the "if-converted" method. Under this method, the periodic interest expense (net of applicable taxes) for dilutive notes is added back to the numerator and the number of shares that the notes are entitled to (if converted, regardless of whether they are in or out of the money) are included in the denominator. There were no dilutive instruments for the years ended December 31, 2016 and December 31, 2015.

The following table presents the computation of basic and diluted earnings per common share for the periods indicated (dollar and share amounts in thousands, except per share amounts):



	Twelve Months Ended December 31,
	2017			2016			2015
Basic Earnings per Common Share
Net income attributable to Company	$	91,980		$	67,551		$	78,013
Less: Preferred stock dividends	(15,660		)	(12,900		)	(10,990		)
Net income attributable to Company's common stockholders	$	76,320		$	54,651		$	67,023
Basic weighted average common shares outstanding	111,836			109,594			108,399
Basic Earnings per Common Share	$	0.68		$	0.50		$	0.62

Diluted Earnings per Common Share:
Net income attributable to Company	$	91,980		$	67,551		$	78,013
Less: Preferred stock dividends	(15,660		)	(12,900		)	(10,990		)
Add back: Interest expense on convertible notes for the period, net of tax	9,158			—			—
Net income attributable to Company's common stockholders	$	85,478		$	54,651		$	67,023
Weighted average common shares outstanding	111,836			109,594			108,399
Net effect of assumed convertible notes conversion to common shares	18,507			—			—
Diluted weighted average common shares outstanding	130,343			109,594			108,399
Diluted Earnings per Common Share	$	0.66		$	0.50		$	0.62