Share-Based Payments (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 6 Months Ended | |
Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2016 | Mar. 31, 2015 | Mar. 31, 2016 |
Restricted Stock [Member] | | | | | |
Director Fee Plan, aggregate disclosures [Abstract] | | | | | |
Restricted stock awards unvested (in shares) | | | | | 31,787 |
Director Fee Plan [Member] | | | | | |
Stock option activity [Roll Forward] | | | | | |
Outstanding, end of period (in shares) | 0 | | 0 | | |
Director Fee Plan, aggregate disclosures [Abstract] | | | | | |
Shares deferred under the Director Fee Plan (in shares) | | | | | 17,005 |
Value of annual stock based grant | | | $ 110 | | |
Total stock options granted to date (in shares) | | | | | 22,300 |
Option awards outstanding (in shares) | 0 | | 0 | | 0 |
Total restricted stock awards granted to date (in shares) | | | | | 152,290 |
Restricted stock awards unvested (in shares) | | | | | 49,140 |
All Plans [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Total stock-based compensation cost | $ 2,741 | $ 2,039 | $ 5,267 | $ 4,564 | |
Future income tax benefit from compensation expense recognized | $ 1,069 | 795 | 2,054 | 1,780 | |
Cash received from stock options exercised | | 51 | 1,798 | 3,778 | |
Tax benefit realized from options exercised | | $ 6 | $ 283 | 321 | |
All Plans [Member] | Stock Options [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 33.00% | | |
Expiration period | | | 10 years | | |
Stock options exercised (in shares) | 0 | | 47,834 | | |
Restricted stock activity [Roll Forward] | | | | | |
Expired or forfeited (in shares) | | | (89,240) | | |
Stock option activity [Roll Forward] | | | | | |
Outstanding, beginning of period (in shares) | | | 337,938 | | |
Exercised (in shares) | 0 | | (47,834) | | |
Expired or forfeited (in shares) | | | (98,745) | | |
Outstanding, end of period (in shares) | 191,359 | | 191,359 | | |
Exercisable (in shares) | 114,193 | | 114,193 | | |
Outstanding, weighted-average exercise price, beginning of period (in dollars per share) | | | $ 39.19 | | |
Exercised, weighted-average exercise price (in dollars per share) | | | 37.59 | | |
Expired or forfeited, weighted-average exercise price (in dollars per share) | | | 37.33 | | |
Outstanding, weighted-average exercise price, end of period (in dollars per share) | $ 40.56 | | $ 40.56 | | |
Exercisable, weighted-average exercise price (in dollars per share) | | | | | $ 40.56 |
Outstanding, weighted-average remaining contractual term | | | 7 months 6 days | | |
Outstanding, aggregate intrinsic value | | | | | $ 2,089 |
Exercisable, weighted-average remaining contractual term | | | 7 months 6 days | | |
Exercisable, aggregate intrinsic value | | | | | $ 1,246 |
Intrinsic value of options exercised | | | $ 744 | $ 856 | |
Non-vested options activity [Roll Forward] | | | | | |
Non-vested at beginning of period (in shares) | | | 166,406 | | |
Expired or forfeited (in shares) | | | (89,240) | | |
Non-vested at end of period (in shares) | 77,166 | | 77,166 | | |
Non-vested, weighted-average grant-date fair value, beginning of period (in dollars per share) | | | $ 12.43 | | |
Expired or forfeited, weighted-average grant-date fair value (in dollars per share) | | | 12.56 | | |
Non-vested, weighted-average grant-date fair value, end of period (in dollars per share) | $ 12.29 | | $ 12.29 | | |
Director Fee Plan, aggregate disclosures [Abstract] | | | | | |
Option awards outstanding (in shares) | 191,359 | | 337,938 | | 191,359 |
All Plans [Member] | Stock Options [Member] | After 3 Years [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 33.00% | | |
Vesting period | | | 3 years | | |
All Plans [Member] | Stock Options [Member] | After 4 Years [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 33.00% | | |
Vesting period | | | 4 years | | |
All Plans [Member] | Stock Options [Member] | After 5 Years [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 33.00% | | |
Vesting period | | | 5 years | | |
All Plans [Member] | Restricted Stock [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Expiration period | | | 5 years | | |
Restricted stock activity [Roll Forward] | | | | | |
Non-vested at beginning of period (in shares) | | | 570,567 | | |
Granted (in shares) | | | 224,125 | | |
Vested (in shares) | | | (260,947) | | |
Expired or forfeited (in shares) | | | (3,385) | | |
Non-vested at end of period (in shares) | 530,360 | | 530,360 | | |
Non-vested weighted-average grant-date fair value, beginning of period (in dollars per share) | | | $ 33.66 | | |
Granted, weighted-average grant-date fair value (in dollars per share) | | | 51.91 | | |
Vested, weighted-average grant-date fair value (in dollars per share) | | | 30.17 | | |
Expired or forfeited, weighted-average grant-date fair value (in dollars per share) | | | 39.55 | | |
Non-vested weighted-average grant-date fair value, end of period (in dollars per share) | $ 45.21 | | $ 45.21 | | |
Non-vested options activity [Roll Forward] | | | | | |
Expired or forfeited (in shares) | | | (3,385) | | |
Unrecognized compensation cost [Abstract] | | | | | |
Unrecognized compensation cost on non-vested awards | | | | | $ 13,497 |
Weighted average period of recognition of unrecognized compensation cost on non-vested awards | | | 1 year 9 months 18 days | | |
Fair value assumptions [Abstract] | | | | | |
Expected volatility | | | 20.70% | 22.20% | |
Dividend yield | | | 1.00% | 1.00% | |
Average risk-free interest rate | | | 1.70% | 1.70% | |
Average expected term | | | 2 years 1 month 6 days | 1 year 9 months 18 days | |
All Plans [Member] | Restricted Stock [Member] | After 3 Years [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 50.00% | | |
Vesting period | | | 3 years | | |
All Plans [Member] | Restricted Stock [Member] | Attainment of Pre-Defined Levels of Appreciation in Market Value [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 16.66% | | |
All Plans [Member] | Restricted Stock [Member] | Fiscal 2013 and Thereafter [Member] | After 3 Years [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 50.00% | | |
Vesting period | | | 3 years | | |
All Plans [Member] | Restricted Stock [Member] | Fiscal 2013 and Thereafter [Member] | Attainment of Pre-Defined Levels of Appreciation in Market Value [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 8.33% | | |
All Plans [Member] | Restricted Stock [Member] | Fiscal 2013 and Thereafter [Member] | Attainment of Pre-Defined Levels of Adjusted Earnings Per Share [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Vesting percentage | | | 8.33% | | |
2012 Equity Incentive Plan [Member] | | | | | |
Share-based compensation, aggregate disclosures [Abstract] | | | | | |
Term of plan | | | 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) | | | | | 1,028,548 |
2014 Director Fee Plan [Member] | | | | | |
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 | | |