Share-based Compensation - Additional Information (Detail) - shares	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares issued under stock purchase plan, stock option exercises and restricted stock	214,679	203,398

Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

No definition available.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration