CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Cash flows from operating activities
Net income	$ 39,239,000	$ 31,337,000	$ 20,425,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,202,000	6,801,000	6,759,000
Amortization	10,061,000	9,124,000	5,687,000
Stock-based compensation expense	3,733,000	3,840,000	3,350,000
Amortization of debt issuance costs	345,000	373,000	321,000
Loss on disposal of fixed assets	184,000	105,000	10,000
Impairment of convertible notes receivable		605,000
Deferred income taxes	(368,000)	370,000	(1,799,000)
Excess tax benefits from stock-based compensation	(2,875,000)	(1,970,000)	(776,000)
Changes in assets and liabilities, net of assets acquired and liabilities assumed:
Accounts receivable	(2,447,000)	2,307,000	(13,449,000)
Inventories	(5,262,000)	(2,227,000)	(2,038,000)
Prepaid expenses and other current assets	(1,387,000)	(345,000)	(418,000)
Accounts payable and other current liabilities	(1,561,000)	(177,000)	7,266,000
Income taxes	4,630,000	437,000	2,860,000
Net cash provided by operating activities	51,494,000	50,580,000	28,198,000
Cash flows from investing activities
Capital expenditures	(6,745,000)	(5,502,000)	(5,835,000)
Proceeds from disposal of fixed assets	32,000	9,000	78,000
Acquisition of Byrne		(95,261,000)
Acquisition of ConFirm		(855,000)	(7,500,000)
Acquisition of Gambro		(1,550,000)	(22,150,000)
Acquisition of SPS Business, net of cash acquired	(35,415,000)
Acquisition of Polyp Trap	(486,000)
Acquisition of Eagle Pure Water	(870,000)
Acquisition of Siemens Water	(8,300,000)
Other, net	(262,000)	44,000	(314,000)
Net cash used in investing activities	(52,046,000)	(103,115,000)	(35,721,000)
Cash flows from financing activities
Borrowings under term loan facility, net of debt issuance costs		49,647,000
Borrowings under revolving credit facility, net of debt issuance costs	45,000,000	46,941,000	28,000,000
Repayments under term loan facility	(10,000,000)	(10,000,000)	(10,000,000)
Repayments under revolving credit facility	(30,000,000)	(22,000,000)	(15,000,000)
Proceeds from exercises of stock options	1,817,000	2,372,000	2,555,000
Dividends paid	(3,016,000)	(2,523,000)	(2,064,000)
Excess tax benefits from stock-based compensation	2,875,000	1,970,000	776,000
Repurchases of shares	(2,252,000)	(1,904,000)	(1,290,000)
Net cash provided by financing activities	4,424,000	64,503,000	2,977,000
Effect of exchange rate changes on cash and cash equivalents	18,000	(192,000)	344,000
Increase (decrease) in cash and cash equivalents	3,890,000	11,776,000	(4,202,000)
Cash and cash equivalents at beginning of year	30,186,000	18,410,000	22,612,000
Cash and cash equivalents at end of year	$ 34,076,000	$ 30,186,000	$ 18,410,000