Recent Accounting Developments - Additional Information (Detail)	6 Months Ended
Jun. 30, 2017 USD ($)
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncement Early Adoption [Line Items]
Recognized tax benefit in income tax expense related to vesting of restricted stock awards and exercised stock options	$ 198,000

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration