v2.4.0.6
Guaranteed Preferred Beneficial Interest in Company's Junior Subordinated Debentures - Summary of Financial Information of Trust (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Schedule of Investments [Line Items]    
Total assets $ 1,175,793 $ 1,127,851
Stockholder's equity - trust common securities 270,495 278,547
Total liabilities and stockholders' equity 1,175,793 1,127,851
Preferred Junior Subordinated Debentures [Member]
    
Schedule of Investments [Line Items]    
Non-current assets-junior subordinated debentures 111,871  
Common Junior Subordinated Debentures [Member]
    
Schedule of Investments [Line Items]    
Non-current assets-junior subordinated debentures 3,261  
Trust Preferred Securities [Member]
    
Schedule of Investments [Line Items]    
Non-current liabilities - trust preferred securities 111,871  
Common Trust Securities [Member]
    
Schedule of Investments [Line Items]    
Stockholder's equity - trust common securities 3,261  
Trust Securities [Member]
    
Schedule of Investments [Line Items]    
Total liabilities and stockholders' equity 115,132  
Junior Subordinated Debentures [Member]
    
Schedule of Investments [Line Items]    
Total assets $ 115,132