Subsequent Events - Additional Information (Detail) - 5 1/2% Senior Notes Due 2021 [Member] - Subsequent Event [Member]	Apr. 15, 2019 USD ($)
Debt, redemption price percentage	100.00%
Debt instrument,redeemed principal amount	$ 150,000,000
Debt instrument principal amount outstanding	50,000,000
Debt instrument,redemption face amount	1,000
Cash [Member]
Redemption of senior notes	117,900,000
Revolving Credit [Member]
Redemption of senior notes	$ 32,100,000