Stockholders' Equity - Additional Information (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Shares reserved for issuance under the Directors Deferred Fee Plan	229,679	244,835

Number of common shares reserved for future issuance related to deferred compensation arrangements with individuals.

No definition available.

Name:	us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant