Annual report pursuant to Section 13 and 15(d)

Fair Value of Financial Instruments - Fair Values and Related Carrying Values of Debt Instruments (Detail)

v3.19.1
Fair Value of Financial Instruments - Fair Values and Related Carrying Values of Debt Instruments (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Jan. 22, 2014
Jul. 30, 2013
6.75% Notes        
Long-term Debt        
Debt instrument fixed interest rate 6.75%   6.75%  
7.50% Notes        
Long-term Debt        
Debt instrument fixed interest rate 7.50%     7.50%
Carrying Amount        
Long-term Debt        
Long-term Debt $ 585,000 $ 585,000    
Carrying Amount | 6.75% Notes        
Long-term Debt        
Long-term Debt 360,000 360,000    
Carrying Amount | 7.50% Notes        
Long-term Debt        
Long-term Debt 225,000 225,000    
Fair Value        
Long-term Debt        
Long-term Debt 297,000 502,538    
Fair Value | 6.75% Notes        
Long-term Debt        
Long-term Debt 180,000 296,100    
Fair Value | 7.50% Notes        
Long-term Debt        
Long-term Debt $ 117,000 $ 206,438