Annual report pursuant to Section 13 and 15(d)

Long-Term Incentive Plans - Additional Information (Detail)

v2.4.0.8
Long-Term Incentive Plans - Additional Information (Detail) (USD $)
 12 Months Ended 12 Months Ended 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
Incentive Plans [Member]
Dec. 31, 2012
Incentive Plans [Member]
Dec. 31, 2011
Incentive Plans [Member]
Dec. 31, 2013
Non-employee directors [Member]
Dec. 31, 2013
Employee [Member]
Dec. 31, 2013
Employee Stock Option [Member]
Feb. 13, 1997
Employee Stock Option [Member]
Dec. 31, 2013
Employee Stock Option [Member]
Long Term Incentive Plan 2002 [Member]
Apr. 24, 2002
Employee Stock Option [Member]
Long Term Incentive Plan 2002 [Member]
Dec. 31, 2013
Employee Stock Option [Member]
Long Term Incentive Plan 2011 [Member]
Apr. 28, 2011
Employee Stock Option [Member]
Long Term Incentive Plan 2011 [Member]
Feb. 13, 1997
Employee Stock Option [Member]
Maximum [Member]
Apr. 24, 2002
Employee Stock Option [Member]
Maximum [Member]
Long Term Incentive Plan 2002 [Member]
Apr. 28, 2011
Employee Stock Option [Member]
Maximum [Member]
Long Term Incentive Plan 2011 [Member]
Dec. 31, 2013
Non Performance Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock options authorized for grant                   1,000,000   500,000   500,000        
Stock options granted, term                 10 years   10 years   10 years          
Stock options available for grant per individual employee                             400,000 200,000 200,000  
Available shares for future issuance 496,000                                  
Options exercised total intrinsic value $ 26,000 $ 250,000 $ 133,000                              
Proceeds from exercise of stock options 203,000 17,000 167,000                              
Excess tax benefit from share-based payment arrangements 116,000 259,000 146,000                              
Restricted stock vesting period minimum                                   3 years
Restricted stock granted annual installments beginning first anniversary of the date of grant             20.00% 33.33%                    
Restricted stock granted 100,150 60,250 67,600                              
Restricted stock weighted average grant date fair value $ 23.22 $ 23.53 $ 28.43                              
Total unrecognized compensation costs 3,100,000                                  
Recognition of compensation cost weighted average period 3 years 10 months 24 days                                  
Total fair value of shares vested 1,300,000                                  
Compensation expense-stock compensation plans 672,000 (259,000) (146,000) 671,000 1,200,000 906,000                        
Total income tax benefit under share-base compensation $ 116,000 $ 297,000 $ 238,000