Summary of Restricted Stock Award Activity (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock unit awards that vested during the period	198,711
Fair value of restricted shares that vested during the period	$ 7,630	$ 7,815
Compensation expense recognized during the period	4,869	4,798
Income tax benefit recognized upon vesting of restricted stock awards	$ 1,473	$ 1,751
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock unit awards that vested during the period	88,074	127,084
Fair value of restricted shares that vested during the period	$ 3,550	$ 4,846
Accumulated dividends paid upon vesting of restricted stock unit awards	375	501
Compensation expense recognized during the period	1,777	2,080
Income tax benefit recognized upon vesting of restricted stock awards	$ 170	$ 740

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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