Rights Agreement - Additional Information (Detail) - $ / shares				12 Months Ended
	May 06, 2019	May 05, 2019	May 18, 2016	Dec. 31, 2020	Dec. 31, 2019
Class Of Warrant Or Right [Line Items]
Conversion basis of dividend distribution				one preferred share purchase right (a “Right”) for each outstanding share of common stock
Common stock, par value			$ 0.01	$ 0.01	$ 0.01
Dividend payable date				May 31, 2016
Rights agreement expiration date	May 18, 2022	May 18, 2019
Purchase price	$ 13.39	$ 13.86
Right agreement exemption minimum business days	10 days
Right agreement exemption maximum business days	20 days
Preferred stock, par value				$ 0.01	$ 0.01
Common stock acquisition beneficial ownership percentage			4.99%
Series A Junior Participating Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Purchase price			$ 13.39
Preferred stock, par value			$ 0.01