Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Share-Based Payment (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2017
Stock options
Fair value assumptions, Black-Scholes
Expiration period	10 years
Vesting period	3 years
Expected dividend yield	0.00%	0.00%
Stock options \| Officers And Employees
Fair value assumptions, Black-Scholes
Vesting period	3 years
RSUs \| 2014 PSP
Fair value assumptions, Black-Scholes
Vesting period	3 years
RSUs \| 2016 PSP
Fair value assumptions, Black-Scholes
Vesting period	3 years
RSUs \| 2017 PSP
Fair value assumptions, Black-Scholes
Vesting period	3 years
RSUs \| 2018 PSP
Fair value assumptions, Black-Scholes
Vesting period	3 years
RSUs \| 2019 PSP
Fair value assumptions, Black-Scholes
Vesting period	3 years
Restricted shares \| Officers And Employees \| Minimum
Fair value assumptions, Black-Scholes
Vesting period	3 years
Restricted shares \| Officers And Employees \| Maximum
Fair value assumptions, Black-Scholes
Vesting period	8 years
Restricted shares \| Non-Employee Directors
Fair value assumptions, Black-Scholes
Vesting period	1 year