Organization and Summary of Significant Accounting Policies - Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basic EPS impact from tax benefit from US tax reform										$ 1.92
Diluted EPS impact from tax benefit from US tax reform										$ 1.91
Weighted average number diluted shares excluded from calculation										2,303,000	1,567,000
Income (numerator):
Net income - basic and diluted	$ 841,914	[1]	$ 10,621	$ (63,557)	$ 469	$ 27,670	$ (109,621)	$ (119,402)	$ (198,326)	$ 789,447	$ (399,679)		$ (353,668)
Weighted average shares - basic										371,066,000	370,380,000		369,540,000
Non-vested restricted stock										2,702,000	0	[2]	0	[2]
Weighted average shares - diluted										373,768,000	370,380,000		369,540,000
Net income per share:
Basic (in dollars per share)	$ 2.27		$ 0.03	$ (0.17)	$ 0.00	$ 0.07	$ (0.30)	$ (0.32)	$ (0.54)	$ 2.13	$ (1.08)		$ (0.96)
Diluted (in dollars per share)	$ 2.25		$ 0.03	$ (0.17)	$ 0.00	$ 0.07	$ (0.30)	$ (0.32)	$ (0.54)	$ 2.11	$ (1.08)		$ (0.96)

[1] Fourth quarter 2017 results reflect the remeasurement of the Company's deferred income tax assets and liabilities in response to the enactment of the Tax Reform Act in December 2017, which resulted in a one-time decrease in income tax expense and corresponding increase in net income of approximately $713.7 million ($1.92 per basic share and $1.91 per diluted share). See Note 8. Income Taxes for further discussion.

[2] For the years ended December 31, 2016 and 2015, the Company had a net loss and therefore the potential dilutive effect of approximately 2,303,000 and 1,567,000 weighted average non-vested restricted shares, respectively, were not included in the calculation of diluted net loss per share because to do so would have been anti-dilutive to the computations.