Geographic Area Information - Geographical Information Pertaining to Company's Operating Revenues (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	$ 27,623	$ 19,009
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	19,562	12,415
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	3,321	2,301
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	2,691	2,559
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	1,509	1,399
Asia/Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	$ 540	$ 335