Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income	$ 27,557	$ 25,054	$ 27,010
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,676	10,788	9,497
Share-based compensation expense	6,253	6,132	5,045
Provision for losses - accounts receivable	805	1,161	1,538
Excess tax benefit from exercises of share-based arrangements	(3,590)	(2,000)	(1,125)
Deferred income tax benefit	(2,916)	(959)	(1,730)
Changes in operating assets and liabilities, exclusive of effects of acquired companies:
Accounts receivable	(8,544)	(1,989)	(6,277)
Income tax payable	6,084	(34)	1,391
Prepaid expenses and other current assets	(214)	104	1,377
Accounts payable	575	(1,181)	1,190
Accrued liabilities	4,887	(5,200)	1,960
Deferred revenue	14,862	3,474	3,065
Net cash provided by operating activities	56,435	35,350	42,941
Cash flows from investing activities:
Proceeds from sales of investments	50	75	2,500
Cost of acquisitions, net of cash acquired	(17,298)	(9,661)	(2,934)
Additions to property and equipment	(12,278)	(4,930)	(12,352)
Decrease (increase) in restricted investments		6,000	(918)
Decrease (increase) in other	717	(178)	46
Net cash used by investing activities	(28,809)	(8,694)	(13,658)
Cash flows from financing activities:
Increase (decrease) in net borrowings on revolving line of credit	34,200	26,500	(8,000)
Purchase of treasury shares	(71,802)	(65,793)	(18,263)
Contributions from employee stock purchase plan	2,045	1,901	1,494
Proceeds from exercise of stock options	3,553	3,181	2,295
Debt Issuance costs		(2,027)
Excess tax benefits from exercise of share-based arrangements	3,590	2,000	1,125
Net cash used by financing activities	(28,414)	(34,238)	(21,349)
Net (decrease) increase in cash and cash equivalents	(788)	(7,582)	7,934
Cash and cash equivalents at beginning of year	2,114	9,696	1,762
Cash and cash equivalents at end of year	$ 1,326	$ 2,114	$ 9,696

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).