Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - shares	Sep. 30, 2019	Sep. 30, 2018
Summary Of Shares Repurchased Under Stock Purchase Program [Abstract]
Shares remaining to be repurchased	148,736	300,000

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

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