Calculation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
BASIC EPS:
Net loss	$ (92,184)	$ (85,866)	$ (155,723)	$ (156,369)
Adjust for loss attributed to holders of non-vested restricted stock		846		1,526
Loss attributed to other common stockholders	$ (92,184)	$ (85,020)	$ (155,723)	$ (154,843)
Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock	201,204	145,944	180,747	145,857
Basic net loss per common share	$ (0.46)	$ (0.58)	$ (0.86)	$ (1.06)
DILUTED EPS:
Loss attributed to other common stockholders	$ (92,184)	$ (85,020)	$ (155,723)	$ (154,843)
Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock	201,204	145,944	180,747	145,857
Weighted average number of diluted common shares outstanding	201,204	145,944	180,747	145,857
Diluted net loss per common share	$ (0.46)	$ (0.58)	$ (0.86)	$ (1.06)
Potentially dilutive securities excluded as anti-dilutive	9,475	9,370	9,475	9,370