XML 92 R81.htm IDEA: XBRL DOCUMENT v3.20.2
Long-Term Debt (Convertible Senior Notes) - Additional Information (Detail)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended
Sep. 30, 2020
USD ($)
$ / shares
Sep. 30, 2019
USD ($)
$ / shares
Jun. 30, 2020
USD ($)
Sep. 30, 2020
USD ($)
$ / shares
Sep. 30, 2019
USD ($)
$ / shares
Debt Instrument [Line Items]          
Cash dividends on common stock | $ / shares $ 0.40 $ 0.40   $ 1.20 $ 1.20
Debt instrument loss from repurchase amount | $ $ 0 $ 0   $ 150 $ 0
4.25% Convertible Senior Notes [Member]          
Debt Instrument [Line Items]          
Debt instrument stated interest rate 4.25%     4.25%  
Convertible debt, conversion ratio       16.42  
Convertible debt, conversion price | $ / shares $ 60.91     $ 60.91  
Debt Instrument, principal amount repurchased | $     $ 4,550    
Debt instrument loss from repurchase amount | $     $ 150    
Debt discount, remaining amortization period       1 year 4 months 24 days  
4.25% Convertible Senior Notes [Member] | Minimum [Member]          
Debt Instrument [Line Items]          
Cash dividends on common stock | $ / shares       $ 0.35