Quarterly Financial Information (Unaudited)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information (Unaudited) [Abstract]

Quarterly Financial Information (Unaudited)

Quarterly Financial Information (Unaudited)

	First		Second		Third		Fourth
	(In Thousands, Except Per Share Data)
Year ended December 31, 2017
Operating revenue	$	129,903	$	129,616	$	182,114	$	165,703
Operating income	19,363		21,313		12,999		9,869
Income before income taxes	19,651		21,737		13,062		10,048
Net income	14,036		14,616		7,916		38,605
Net income per share, basic	0.17		0.18		0.10		0.45
Net income per share, diluted	0.17		0.18		0.09		0.45
Year ended December 31, 2016
Operating revenue	$	162,786	$	160,791	$	149,316	$	140,044
Operating income	20,250		24,507		19,913		20,898
Income before income taxes	20,325		24,616		20,037		21,071
Net income	14,377		16,368		12,527		13,114
Net income per share, basic	0.17		0.20		0.15		0.16
Net income per share, diluted	0.17		0.20		0.15		0.16