Annual report pursuant to Section 13 and 15(d)

SHARE-BASED PAYMENTS - Narrative (Details)

v3.5.0.2
SHARE-BASED PAYMENTS - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2014
Share-based compensation, aggregate disclosures [Abstract]      
Future income tax benefit from compensation expense recognized $ 1,720 $ 418 $ 0
All Plans      
Share-based compensation, aggregate disclosures [Abstract]      
Total stock-based compensation cost 10,612 9,097 6,812
Future income tax benefit from compensation expense recognized 4,139 3,548 2,657
Cash received from stock options exercised 6,406 4,015 7,951
Tax benefit realized from options exercised $ 932 $ 350 698
All Plans | Stock Options      
Share-based compensation, aggregate disclosures [Abstract]      
Expiration period (in years) 10 years    
Options vested (in shares) 0 0  
Intrinsic value of options exercised $ 2,692 $ 931 $ 1,653
All Plans | Stock Options | After 3 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 33.33%    
All Plans | Stock Options | After 4 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 33.33%    
Vesting period (in years) 4 years    
All Plans | Stock Options | After 5 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 33.33%    
Vesting period (in years) 5 years    
All Plans | Restricted Stock      
Share-based compensation, aggregate disclosures [Abstract]      
Expiration period (in years) 5 years    
Unrecognized compensation cost on unvested awards $ 8,652    
Weighted average period of recognition of unrecognized compensation cost on non-vested awards 1 year 7 months 6 days    
All Plans | Restricted Stock | After 3 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting period (in years) 3 years    
All Plans | Restricted Stock | Prior to Fiscal Year 2013 | After 3 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 50.00%    
All Plans | Restricted Stock | Prior to Fiscal Year 2013 | After 4 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 16.67%    
All Plans | Restricted Stock | Prior to Fiscal Year 2013 | After 5 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 16.67%    
All Plans | Restricted Stock | Prior to Fiscal Year 2013 | After 6 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 16.66%    
All Plans | Restricted Stock | Fiscal 2013 and Thereafter | After 3 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 50.00%    
2012 Equity Incentive Plan      
Share-based compensation, aggregate disclosures [Abstract]      
Term of plan (in years) 10 years    
Maximum number of shares available for grants or awards (in shares) 2,500,000    
Shares reserved for future issuance under award plan (in shares) 1,022,548    
Pre-defined Levels of Adjusted Earnings Per Share | Restricted Stock | Fiscal 2013 and Thereafter | After 4 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Pre-defined Levels of Adjusted Earnings Per Share | Restricted Stock | Fiscal 2013 and Thereafter | After 5 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Pre-defined Levels of Adjusted Earnings Per Share | Restricted Stock | Fiscal 2013 and Thereafter | After 6 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Pre-defined Levels of Appreciation in the Market Value of Common Stock | Restricted Stock | Fiscal 2013 and Thereafter | After 4 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Pre-defined Levels of Appreciation in the Market Value of Common Stock | Restricted Stock | Fiscal 2013 and Thereafter | After 5 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Pre-defined Levels of Appreciation in the Market Value of Common Stock | Restricted Stock | Fiscal 2013 and Thereafter | After 6 Years      
Share-based compensation, aggregate disclosures [Abstract]      
Vesting percentage 8.33%    
Director Fee Plans      
Director Fee Plan, aggregate disclosures [Abstract]      
Shares deferred under the director fee plan (in shares) 17,005    
Value of annual stock-based grant $ 110    
Option awards outstanding and vested (in shares) 0    
Total restricted stock awards granted to date (in shares) 152,290    
Restricted stock awards unvested (in shares) 29,492    
Director Fee Plans | Stock Options      
Director Fee Plan, aggregate disclosures [Abstract]      
Total stock options granted to date (in shares) 22,300    
2014 Director Fee Plan      
Share-based compensation, aggregate disclosures [Abstract]      
Shares reserved for future issuance under award plan (in shares) 150,000    
Director Fee Plan, aggregate disclosures [Abstract]      
Annual retainer fee paid to non-employee directors $ 75    
Annual retainer fee paid to non-employee chairman of the board $ 175    
Total restricted stock awards granted to date (in shares) 49,140