Annual report pursuant to Section 13 and 15(d)

Share Repurchase Program - Additional Information (Detail)

v3.19.3.a.u2
Share Repurchase Program - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Feb. 06, 2018
Class of Stock [Line Items]    
Stock repurchase program expiration date Feb. 06, 2021  
Class A Common Stock [Member]    
Class of Stock [Line Items]    
Stock repurchase program authorized amount   $ 150.0