Stock-based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	3 Months Ended	12 Months Ended	18 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Feb. 28, 2014	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2015
Stock-Based Compensation Activity [Line Items]
Unrecognized compensation costs related to non-vested awards	$ 2,700,000		$ 2,700,000					2,700,000
Weighted average period for recognition of compensation costs related to non-vested awards			2 years 2 months 12 days
Performance share awards fully expensed	400,000		400,000					400,000
Weighted average per share fair value of stock options	$ 8.72	$ 7.61	$ 7.23	$ 8.72
Dividend yield	0.00%	0.00%	0.00%	0.00%
Total pre-tax intrinsic value of options exercised	1,200,000	900,000	1,400,000	1,300,000
Stock option related expense		600,000		600,000
Performance Shares, time period			3 years
Stock compensation expenses recognized	686,000	1,649,000	1,211,000	2,462,000
Former Chairman of the Board [Member]
Stock-Based Compensation Activity [Line Items]
Restricted stock expense					200,000
Fiscal 2015 (2015 - 2017) [Member]
Stock-Based Compensation Activity [Line Items]
Performance period start year			2015
Performance period end year			2017
Fiscal 2014 (2014 - 2016) [Member]
Stock-Based Compensation Activity [Line Items]
Performance period start year			2014
Performance period end year			2016
Fiscal 2013 (2013 - 2015) [Member]
Stock-Based Compensation Activity [Line Items]
Performance period start year			2013
Performance period end year			2015
Fiscal 2012 (2012 - 2014) [Member]
Stock-Based Compensation Activity [Line Items]
Performance period start year			2012
Performance period end year			2014
Maximum [Member]
Stock-Based Compensation Activity [Line Items]
Restricted stock expense	100,000	200,000	100,000	200,000
Expense recognized related to Performance Shares	200,000	300,000	300,000	500,000
Maximum [Member] | 2009 Equity Incentive Plan [Member]
Stock-Based Compensation Activity [Line Items]
Stock compensation expenses recognized	100,000	100,000	100,000	100,000
Nonqualified Stock Options [Member]
Stock-Based Compensation Activity [Line Items]
Vesting terms			Non-qualified stock options generally become exercisable with respect to 25% of the shares on each of the first four anniversaries following the grant date
Nonqualified Stock Options [Member] | Board of Director [Member]
Stock-Based Compensation Activity [Line Items]
Stock option exercisable on a pro-rata basis			1 year
Nonqualified Stock Options [Member] | Minimum [Member] | Board of Director [Member]
Stock-Based Compensation Activity [Line Items]
Stock option expiration term upon expiration of employment or service			7 years
Nonqualified Stock Options [Member] | Maximum [Member] | Board of Director [Member]
Stock-Based Compensation Activity [Line Items]
Stock option expiration term upon expiration of employment or service			10 years
Performance Shares [Member]
Stock-Based Compensation Activity [Line Items]
Issuance of shares						98,093
Performance Shares [Member] | Fiscal 2015 (2015 - 2017) [Member]
Stock-Based Compensation Activity [Line Items]
Fair value of performance shares for grants awarded			900,000
Performance Shares [Member] | Fiscal 2014 (2014 - 2016) [Member]
Stock-Based Compensation Activity [Line Items]
Fair value of performance shares for grants awarded			900,000
Performance Shares [Member] | Fiscal 2013 (2013 - 2015) [Member]
Stock-Based Compensation Activity [Line Items]
Fair value of performance shares for grants awarded			900,000
Performance Shares [Member] | Maximum [Member]
Stock-Based Compensation Activity [Line Items]
Issuance of shares						124,994
1999 Employee Stock Purchase Plan [Member]
Stock-Based Compensation Activity [Line Items]
Annual compensation withheld, maximum limit			25,000
1999 Employee Stock Purchase Plan [Member] | Maximum [Member]
Stock-Based Compensation Activity [Line Items]
Common stock authorized, shares			400,000
Annual compensation withheld			10.00%
Employee contributions	100,000	100,000	100,000	100,000				100,000
Stock compensation expenses recognized	100,000			100,000
Restricted Stock Units (RSUs) [Member] | 2009 Equity Incentive Plan [Member]
Stock-Based Compensation Activity [Line Items]
Stock compensation expenses recognized		200,000		300,000
Number of stock units awarded			10,678					35,512
Number of stock units forfeited	3,068		3,068				3,417
Number of stock units issued	7,681		7,681				2,183
Additional Stock-based compensation expenses		200,000		200,000
Restricted Stock Units (RSUs) [Member] | Maximum [Member] | 2009 Equity Incentive Plan [Member]
Stock-Based Compensation Activity [Line Items]
Stock compensation expenses recognized	100,000		100,000
Deferred Stock Units [Member] | Director [Member]
Stock-Based Compensation Activity [Line Items]
Number of stock units awarded	1,332
Deferred Stock Units [Member] | 2009 Equity Incentive Plan [Member] | Director [Member]
Stock-Based Compensation Activity [Line Items]
Number of stock units awarded			2,886
Number of deferred stock units issued value			100,000
Deferred Stock Units [Member] | Maximum [Member] | 2009 Equity Incentive Plan [Member] | Director [Member]
Stock-Based Compensation Activity [Line Items]
Number of deferred stock units issued value	$ 100,000
Vesting Anniversary [Member] | Nonqualified Stock Options [Member]
Stock-Based Compensation Activity [Line Items]
Performance share awards, estimated vesting percentage			25.00%
Performance Level [Member] | Minimum [Member]
Stock-Based Compensation Activity [Line Items]
Performance share awards, estimated vesting percentage			20.00%
Performance Level [Member] | Maximum [Member]
Stock-Based Compensation Activity [Line Items]
Performance share awards, estimated vesting percentage			200.00%