Capital Stock - Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income available to common shareholders	$ (389,193)	$ 100,755
Effect of dilutive securities:	0	0
Dilutive net income available to common shareholders	$ (389,193)	$ 100,755
Denominator:
Weighted average basic shares (shares)	187,018,602	187,112,454
Effect of dilutive securities (shares)	0	1,087,257
Weighted average dilutive shares (shares)	187,018,602	188,199,711
Net income per average share attributable to common stockholders - Basic (usd per share)	$ (2.08)	$ 0.54
Net income per average share attributable to common stockholders - Diluted (usd per share)	$ (2.08)	$ 0.54
Securities excluded from computation of EPS (in shares)	1,300,000

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise stock options, restrictive stock units (RSUs), convertible preferred stock of an employee stock ownership plan (ESOP), and other dilutive convertible securities.

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