• Filing Date: 2019-03-08
  • Form Type: 10-K
  • Description: Annual report
v3.10.0.1
Long-Term Debt (Convertible Senior Notes) - Additional Information (Detail)
$ / shares in Units, $ in Thousands
1 Months Ended 12 Months Ended
Mar. 03, 2017
USD ($)
May 31, 2018
$ / shares
Jan. 31, 2015
$ / shares
Dec. 31, 2018
USD ($)
$ / shares
Dec. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2013
USD ($)
Debt Instrument [Line Items]              
Long-term Debt, Gross       $ 264,995 $ 260,061    
3.875% Convertible Senior Notes [Member]              
Debt Instrument [Line Items]              
Debt instrument, stated interest rate       3.875% 3.875%    
Debt conversion date       2019      
Long-term Debt, Gross       $ 89,990 $ 89,990 $ 89,990 $ 103,000
Aggregate amount of debt repurchased           $ 13,010  
Convertible debt, conversion ratio       16.3645      
Convertible debt, conversion price | $ / shares       $ 61.11      
Debt instrument, effective interest rate       8.30%      
Debt discount, remaining amortization period       2 months 15 days      
3.875% Convertible Senior Notes [Member] | Reference Cash Dividend [Member]              
Debt Instrument [Line Items]              
Cash dividends on common stock | $ / shares     $ 0.275        
4.25% Convertible Senior Notes [Member]              
Debt Instrument [Line Items]              
Debt instrument, stated interest rate 4.25%     4.25%      
Debt conversion date       2037      
Long-term Debt, Gross       $ 143,750 143,750    
Proceeds from senior convertible notes net $ 138,775            
Debt issuance and transaction costs 4,975            
Convertible debt, conversion ratio       16.2915      
Convertible debt, conversion price | $ / shares       $ 61.38      
Debt instrument, effective interest rate       7.60%      
Debt discount, remaining amortization period       3 years 2 months 12 days      
Debt Instrument effective Rate       5.40%      
Debt Instrument, Face Amount $ 143,750            
4.25% Convertible Senior Notes [Member] | Reference Cash Dividend [Member]              
Debt Instrument [Line Items]              
Cash dividends on common stock | $ / shares   $ 0.35          
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      
Convertible Senior Notes [Member]              
Debt Instrument [Line Items]              
Long-term Debt, Gross       $ 233,740 $ 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 each respective 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 each respective 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%