Quarterly Financial Information (unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

Summarized quarterly financial data for the years ended December 31, 2017 and 2016 are presented in the following table. In the following table, the sum of basic and diluted “Loss per common share” for the four quarters may differ from the annual amounts due to the required method of computing weighted average number of shares in the respective periods. Additionally, due to the effect of rounding, the sum of the individual quarterly loss per share amounts may not equal the calculated year loss per share amount (in thousands, except per share data).

	First Quarter		Second Quarter		Third Quarter			Fourth Quarter
Year ended December 31, 2017
Total operating revenues	$	101,863	$	86,191	$	91,549		$	104,056
Total operating expenses		87,632		80,589		94,338			108,431
Operating income (loss)		14,231		5,602		(2,789	)		(4,375	)
Net income (loss)		26,847		11,494		(16,694	)		(13,122	)
Income (loss) per common share:
Basic	$	0.10	$	0.04	$	(0.06	)	$	(0.05	)
Diluted	$	0.10	$	0.04	$	(0.06	)	$	(0.05	)

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
Year ended December 31, 2016
Total operating revenues	$	49,606		$	47,066		$	54,479		$	83,883
Total operating expenses		100,214			84,017			78,678			89,527
Operating loss		(50,608	)		(36,951	)		(24,199	)		(5,644	)
Net loss		(45,534	)		(73,163	)		(25,949	)		(62,089	)
Loss per common share:
Basic and diluted	$	(0.20	)	$	(0.33	)	$	(0.10	)	$	(0.23	)