Quarterly report pursuant to Section 13 or 15(d)

Compensation (Narrative) (Detail)

v3.5.0.2
Compensation (Narrative) (Detail)
 3 Months Ended 6 Months Ended 15 Months Ended
Jun. 30, 2016
USD ($)
Mar. 31, 2016
shares
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
shares
Jun. 30, 2015
USD ($)
Mar. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Stock based compensation | $ $ 800,000   $ 700,000 $ 1,616,000 $ 2,332,000  
Stock options granted, exercisable life       5 years    
Stock, vesting period       3 years    
Cash proceeds from exercise of stock options | $         $ 452,000  
Stock options remainder vesting period           2 years
Shares repurchased | shares   31,808        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares       357,145    
Stock Appreciation Rights (SARs) [Member]            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
egy-Share-based Compensation Arrangement By Share-based Payment Award, Life       5 years    
egy-Share-based Compensation Arrangemet By Share Based Payment Award, Spread 300     300    
egy-Share-based Compensation Arrangement by Share-based Payment Award, Grant Date Share Price | $       $ 1.04    
Stock, vesting period       3 years    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | shares       815,355    
Maximum [Member]            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]            
Stock, vesting period       5 years