Net Income (Loss) Per Common Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Reconciliation of Numerator and Denominator of Income Per Common Share

The reconciliation of the numerator and the denominator of the earnings per common share is as follows:

	Years ended December 31,
(Dollar amounts in thousands, except share and per share data)	2017		2016		2015
Net income	$	55,054	$	75,036	$	85,377
Less: non-forfeitable dividends on restricted stock	10		12		9
Net income available to common shareholders	$	55,044	$	75,024	$	85,368
Weighted average common shares outstanding	72,479,807		74,132,863		77,066,459
Weighted average potential dilutive common shares (1)	392,381		340,506		114,664
Weighted average common shares outstanding—assuming dilution	72,872,188		74,473,369		77,181,123
Net income per common share—basic	$	0.76	$	1.01	$	1.11
Net income per common share—diluted	$	0.76	$	1.01	$	1.11

(1) Potential common shares consist of common stock issuable under the assumed exercise of stock options and RSUs awards using the treasury stock method.