Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Stock-Based Compensation (PSUs, RSUs and Restricted Stock) - Additional Information (Detail) - USD ($) shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,871,000	$ 1,640,000	$ 5,184,000	$ 5,243,000
Market-Based PSUs, RSUs and Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to other than options	11,600,000		$ 11,600,000
Recognition period of unvested compensation expense			2 years 4 months 24 days
Performance-Based PSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to other than options	8,200,000		$ 8,200,000
Recognition period of unvested compensation expense			3 months 18 days
Stock-based compensation expense	$ 0	$ 0	$ 0	$ 0
Stock Options, PSUs, RSUs or Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options available for issuance under shareholders-approved equity plan	2.7		2.7