Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from Operating Activities
NET INCOME	$ 6,596,000	$ 8,198,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,359,000	3,396,000
Loss on disposal of assets	8,000	67,000
Stock compensation expense	297,000	658,000
Write-off of uncollectible accounts	438,000	616,000
Deferred income tax	(120,000)	(194,000)
Changes in operating assets and liabilities
Accounts receivable	2,565,000	(465,000)
Customer deposits	(986,000)	931,000
Prepaid taxes and expenses	3,244,000	(242,000)
Other assets	137,000	(63,000)
Accounts and taxes payable	(1,725,000)	4,803,000
Accrued liabilities	(1,347,000)	(2,526,000)
Net cash provided by operating activities	13,466,000	15,179,000
Cash Flows from Investing Activities
Purchase of property and equipment	(3,404,000)	(6,963,000)
Net cash (used in) investing activities	(3,404,000)	(6,963,000)
Cash Flows from Financing Activities
Purchase of treasury stock	(3,673,000)	(3,673,000)
Tax effect of stock option exercises	1,093,000	284,000
Exercise of common stock options	489,000	481,000
Net cash (used in) financing activities	(2,091,000)	(2,908,000)
Increase in cash and cash equivalents	7,971,000	5,308,000
Cash and cash equivalents at beginning of period	6,597,000	12,269,000
Cash and cash equivalents at end of period	14,568,000	17,577,000
Supplemental Cash Flow Information:
Income taxes paid	$ 110,000	$ 291,000