• Filing Date: 2020-03-06
  • Form Type: 10-K
  • Description: Annual report
v3.19.3.a.u2
Long-Term Debt (Convertible Senior Notes) - Additional Information (Detail)
$ / shares in Units, $ in Thousands
12 Months Ended
Mar. 15, 2019
USD ($)
$ / shares
Mar. 03, 2017
USD ($)
Dec. 31, 2019
USD ($)
$ / shares
Dec. 31, 2018
USD ($)
$ / shares
Dec. 31, 2017
$ / shares
Mar. 31, 2017
Debt Instrument [Line Items]            
Long-term Debt, Gross     $ 173,695 $ 264,995    
Cash dividends on common stock | $ / shares     $ 1.60 $ 1.475 $ 1.40  
4.25% Convertible Senior Notes [Member]            
Debt Instrument [Line Items]            
Debt instrument stated interest rate   4.25% 4.25%     4.25%
Debt conversion date   2037        
Long-term Debt, Gross     $ 143,750 $ 143,750    
Convertible debt, conversion ratio     16.3667      
Convertible debt, conversion price | $ / shares     $ 61.10      
Debt Instrument, Face Amount   $ 143,750        
Proceeds from senior convertible notes net   138,775        
Debt issuance and transaction costs   $ 4,975        
Debt instrument frequency of periodic payment   semiannually in arrears on March 1 and September 1        
Debt instrument, effective interest rate     7.60%      
Debt instrument effective rate till final maturity date     5.40%      
Debt discount, remaining amortization period     2 years 2 months 12 days      
4.25% Convertible Senior Notes [Member] | Debt Instrument, Redemption, Period One [Member]            
Debt Instrument [Line Items]            
Debt instrument put date     Mar. 01, 2022      
4.25% Convertible Senior Notes [Member] | Debt Instrument, Redemption, Period Two [Member]            
Debt Instrument [Line Items]            
Debt instrument put date     Mar. 01, 2027      
4.25% Convertible Senior Notes [Member] | Debt Instrument, Redemption, Period Three [Member]            
Debt Instrument [Line Items]            
Debt instrument put date     Mar. 01, 2032      
4.25% Convertible Senior Notes [Member] | Minimum [Member]            
Debt Instrument [Line Items]            
Cash dividends on common stock | $ / shares     $ 0.35      
3.875% Convertible Senior Notes [Member]            
Debt Instrument [Line Items]            
Debt instrument stated interest rate     3.875%      
Debt conversion date 2019          
Long-term Debt, Gross $ 89,990     89,990    
Debt instrument, last payment, interest $ 1,744          
Convertible debt, conversion ratio 16.4074          
Convertible debt, conversion price | $ / shares $ 60.95          
Convertible Senior Notes [Member]            
Debt Instrument [Line Items]            
Long-term Debt, Gross     $ 143,750 $ 233,740    
Convertible debt, conversion debt description     The holders of the Convertible Senior Notes may convert all or a portion of their Convertible Senior Notes during specified periods as follows: (1) during any calendar quarter commencing after the calendar quarter ending on the dates specified in the indenture, if the last reported sale price of the Company’s common stock for at least 20 trading days during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; (2) during the five business-day period after any ten consecutive trading-day period in which the trading price per $1 principal amount of the Convertible Senior Notes is less than 98% of the product of the last reported sale price and the conversion rate on each such trading day; (3) if specified corporate events, including a change in control, occur; or (4) at any time on or after the dates specified in the indenture.      
Convertible debt, threshold trading days     20      
Convertible debt, threshold consecutive trading days     30      
Convertible debt, threshold percentage of stock trigger price     130.00%      
Convertible Senior Notes [Member] | Convertible Debt Instrument Conversion Period Two [Member]            
Debt Instrument [Line Items]            
Convertible debt, threshold trading days     5 days      
Convertible debt, threshold percentage of stock trigger price     98.00%