Stock Option Plans - Fair Value of Stock Options Granted (Detail) (USD $)	1 Months Ended	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Assumptions used:
Expected dividends
Stock Options [Member]
Assumptions used:
Expected life (in years)		7 years 6 months
Minimum [Member]
Assumptions used:
Risk-free interest rate		1.20%
Expected dividends
Minimum [Member] | Stock Options [Member]
Stock Based Compensation [Line Items]
Fair value of stock option		$ 0.81
Assumptions used:
Risk-free interest rate		1.19%
Expected volatility		26.50%
Maximum [Member]
Assumptions used:
Risk-free interest rate		1.59%
Expected dividends
Maximum [Member] | Stock Options [Member]
Stock Based Compensation [Line Items]
Fair value of stock option		$ 3.94
Assumptions used:
Risk-free interest rate		4.80%
Expected volatility		84.60%