Capital Stock - Additional Information (Detail)	Jan. 05, 2017 right $ / shares shares
Equity [Line Items]
Number of rights issued | right	1
Percentage at which rights are exercisable before adoption	5.00%
Additional amount of shares needed to be purchased for rights to be exercisable, percentage	1.00%
Series B Preferred Stock
Equity [Line Items]
Number of securities called by each right | shares	0.001
Purchase price of stock called by each right | $ / shares	$ 50