Income (Loss) Per Share - Schedule of Basic and Diluted Income (Loss) Per Common Share from Continuing Operations (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Earnings Per Share [Abstract]                      
Net loss from continuing operations applicable to common shares (numerator for basic and diluted calculation) $ 19,209 $ (19,411) $ (19,403) $ (44,944) $ (42,439) $ 15,305 $ (5,058) $ (42,416) $ (64,549) $ (74,608) $ (36,698)
Weighted average number of common shares outstanding for basic income per share (in shares) 60,510,199 60,335,717 60,227,495 49,819,388 49,630,085 49,414,847 49,336,581 48,847,349 57,759,988 49,310,044 48,560,167
Weighted average number of potentially dilutive common shares outstanding (in shares)                 0 0 0
Weighted average number of common shares outstanding for diluted income per share (in shares) 61,091,783 60,335,717 60,227,495 49,819,388 49,630,085 50,226,661 49,336,581 48,847,349 57,759,988 49,310,044 48,560,167
Loss per common share from continuing operations:                      
Basic (in dollar per share) $ 0.32 $ (0.32) $ (0.33) $ (0.90) $ (0.86) $ 0.31 $ (0.11) $ (0.87) $ (1.12) $ (1.51) $ (0.76)
Diluted (in dollar per share) $ 0.31 $ (0.32) $ (0.33) $ (0.90) $ (0.86) $ 0.30 $ (0.11) $ (0.87) $ (1.12) $ (1.51) $ (0.76)