Net Income (Loss) Per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

	Three months ended September 30,					Nine months ended September 30,
In thousands except per share amounts	2017			2016		2017			2016
Net income (loss) available to common stockholders	$	(16,652	)	$	69,557	$	(8,944	)	$	63,660
Weighted average shares:
Basic	179,278			161,039		179,141			155,108
Effect of stock-based compensation plans	—			4,789		—			3,284
Diluted	179,278			165,828		179,141			158,392
Income (loss) per share:
Basic	$	(0.09	)	$	0.43	$	(0.05	)	$	0.41
Diluted	$	(0.09	)	$	0.42	$	(0.05	)	$	0.40