XML 59 R41.htm IDEA: XBRL DOCUMENT v3.4.0.3
Earnings per share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Earnings Per Share [Abstract]    
Net income (loss) attributable to common stockholders $ (22,943) $ 28,672
Average shares outstanding (basic) (in shares) 90,477 89,482
Common stock equivalents (in shares) 0 1,987
Diluted shares (in shares) 90,477 91,469
Basic earnings per share (in dollars per share) $ (0.25) $ 0.32
Diluted earnings per share (in dollars per share) $ (0.25) $ 0.31
Stock Options    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Diluted earnings per share calculation excludes (in shares)   1,600