Stock Compensation - Summary of Changes in Common Stock Options (Detail) (USD $)	6 Months Ended	12 Months Ended
	Dec. 31, 2012	Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock options shares, Beginning balance	2,018,476	2,303,706
Common stock options shares, Granted	113,000	215,000
Common stock options shares, Exercised	(454,926)	(365,705)
Common stock options shares, Surrendered	(57,500)	(134,525)
Common stock options shares, Ending balance	1,619,050	2,018,476
Weighted Average Exercise Price, Beginning balance	$ 5.11	$ 4.83
Weighted Average Exercise Price, Granted	$ 8.57	$ 6.26
Weighted Average Exercise Price, Exercised	$ 4.61	$ 3.95
Weighted Average Exercise Price, Surrendered	$ 6.06	$ 5.17
Weighted Average Exercise Price, Ending balance	$ 5.46	$ 5.11