Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Jun. 30, 2018	Dec. 31, 2016	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020
Equity [Abstract]
Stock repurchase program period		3 years
Stock repurchase program, authorized amount		$ 100.0
Authorized increase and extension in stock repurchase program amount	$ 300.0
Stock repurchase program extended expiration date	2020-12
Shares repurchased			0	0	9,100,000
Shares repurchased average price paid per share					$ 36.93
Remaining authorized repurchase amount			$ 74.2		$ 74.2