Shareholders' Equity - Additional information (Detail) - Stock Repurchase Agreement [Member] $ / shares in Units, $ in Millions	May 01, 2017 USD ($) $ / shares shares
Class of Stock [Line Items]
Common stock, authorized to be repurchased, shares	826,305
Common stock repurchased, per share amount | $ / shares	$ 13.60
Common stock, authorized to be repurchased, value | $	$ 11.2
Common stock owned by trust, shares	36,000