Capital Stock (Tables)

12 Months Ended

Dec. 31, 2017

Equity [Abstract]

Schedule of Earnings Per Share

Earnings per share for the years ended December 31, 2017, 2016, and 2015 respectively, are computed as follows:

	For the Year Ended
	December 31, 2017		December 31, 2016		December 31, 2015
	(dollars in thousands)
Numerator:
Net income available to common shareholders	$	491,184	$	549,494	$	250,349
Effect of dilutive securities:	—		—		—
Dilutive net income available to common shareholders	$	491,184	$	549,494	$	250,349
Denominator:
Weighted average basic shares	187,780,355		187,728,634		199,563,196
Effect of dilutive securities	506,965		296,204		86,981
Weighted average dilutive shares	188,287,320		188,024,838		199,650,177
Net income per average share attributable to common stockholders - Basic	$	2.62	$	2.93	$	1.25
Net income per average share attributable to common stockholders - Diluted	$	2.61	$	2.92	$	1.25