Earnings (loss) per share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Basic and diluted earnings (loss) per share

The following table shows the basic and diluted earnings (loss) per share for 2016, 2015, and 2014:

	For the year ended December 31, 2016
	Net loss			Shares (000)	Per-Share
Net loss	$	(252,415	)
Amount allocated to common stockholders	100		%
Basic and Diluted EPS:
Net loss allocated to common stockholders	$	(252,415	)	87,064	$	(2.90	)

	For the year ended December 31, 2015
	Net loss			Shares (000)	Per-Share
Net loss	$	(59,310	)
Amount allocated to common stockholders	100		%
Basic and Diluted EPS:
Net loss allocated to common stockholders	$	(59,310	)	87,375	$	(0.68	)

	For the year ended December 31, 2014
	Net income			Shares (000)	Per-Share
Net income	$	126,474
Amount allocated to common stockholders	91.81		%
Basic EPS:
Net income allocated to common stockholders	$	116,116		88,823	$	1.31
Effect of dilutive securities:
Share-based compensation plans				605
Diluted EPS:	$	116,116		89,428	$	1.30

Antidilutive securities excluded from calculation of diluted EPS

Securities excluded from the calculation of diluted EPS:
	2016	2015	2014
Stock options (1)	105,453	356,634	320,553
Service-based share awards (1)	840,402	608,914	—

(1) In periods when we report a net loss, all share-based compensation awards are excluded from the calculation of diluted weighted average shares outstanding because of their antidilutive effect on earnings (loss) per share.