Selected Quarterly Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Data [Abstract]

Schedule of selected quarterly data (unaudited)

	First Quarter						Second Quarter						Third Quarter						Fourth Quarter
In thousands, except per share amounts	2018			2017			2018			2017			2018			2017			2018			2017
Revenues	$	81,198		$	94,894		$	69,633		$	94,722		$	63,588		$	94,424		$	70,209		$	99,866
Operating income (loss)	(5,035		)	(6,342		)	(6,308		)	(1,791		)	(10,353		)	950			(4,338		)	(33,682		)
Income (loss) before income taxes	23,849			(8,862		)	(7,318		)	(4,852		)	(11,421		)	(2,098		)	(5,673		)	(35,942		)
Net income (loss)	$	32,629		$	(7,386	)	$	(6,734	)	$	(2,653	)	$	(9,984	)	$	(2,480	)	$	1,639		$	(29,341	)
Basic earnings (loss) per common share	$	5.24		$	(1.20	)	$	(1.10	)	$	(0.43	)	$	(1.62	)	$	(0.40	)	$	0.21		$	(4.73	)
Diluted earnings (loss) per common share	$	4.67		$	(1.20	)	$	(1.10	)	$	(0.43	)	$	(1.62	)	$	(0.40	)	$	0.21		$	(4.73	)