Net Income Per Common Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Net Income Per Common Share [Table Text Block]

The following table sets forth the computation of basic and diluted net income per common share:

	Year Ended December 31
	2016		2015		2014
	(thousands, except per-share data)
Net income	$	38,254	$	52,182	$	80,009
Weighted average common shares outstanding during the period (for basic calculation)	38,761		39,239		39,412
Dilutive effect of other potential common shares	164		116		80
Weighted average common shares and potential common shares (for diluted calculation)	38,925		39,355		39,492
Net income per common share - Basic	$	0.99	$	1.33	$	2.03
Net income per common share - Diluted	$	0.98	$	1.33	$	2.03