Quarterly Results (unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

The following table shows selected quarterly results for the Company.

(in thousands except per share data)

For the year ended December 31, 2016	First		Second			Third			Fourth			Total
Operating revenues	$	92,571	$	130,309		$	156,836		$	155,572		$	535,288
Operating income (loss)	21,312		(7,046		)	(3,929		)	12,189			22,526
Net income (loss)	13,880		(6,995		)	(7,596		)	(184		)	(895		)
Net income (loss) per share – basic	0.29		(0.14		)	(0.16		)	0.00			(0.02		)
Net income (loss) per share – diluted	0.28		(0.14		)	(0.16		)	0.00			(0.02		)
For the year ended December 31, 2015	First		Second			Third			Fourth			Total
Operating revenues	$	84,287	$	85,701		$	85,212		$	87,285		$	342,485
Operating income	18,526		18,750			15,089			21,721			74,086
Net income	10,286		10,474			7,996			12,108			40,864
Net income per share - basic	0.21		0.22			0.17			0.24			0.84
Net income per share - diluted	0.21		0.21			0.17			0.24			0.83