Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 23,676	$ 20,509
Adjustments to reconcile net income to net cash provided by (used in) operating activities-
Depreciation	11,711	12,520
Amortization	21,096	21,215
Amortization of original issue discount	2,429	2,869
Gain on short-term investments and other	(23)	(34)
Deferred income taxes	(6,342)	(1,344)
Excess tax benefit of stock-based compensation awards	(288)	(824)
Stock-based employee compensation	6,529	6,529
Changes in operating assets and liabilities:
Trade accounts and other receivables, net	18,117	(17,769)
Other current and non-current assets	(3,951)	(2,175)
Income taxes payable/receivable	1,842	8,398
Trade accounts payable and accrued liabilities	(3,196)	(28,987)
Deferred revenue	13,168	(22,083)
Net cash provided by (used in) operating activities	84,768	(1,176)
Cash flows from investing activities:
Purchases of property and equipment	(13,550)	(11,061)
Purchases of short-term investments	(24,779)	(19,968)
Proceeds from the sale/maturity of short-term investments	16,800	17,700
Acquisition of and investments in client contracts	(2,948)	(4,479)
Net cash used in investing activities	(24,477)	(17,808)
Cash flows from financing activities:
Proceeds from issuance of common stock	1,007	753
Repurchase of common stock	(13,541)	(4,049)
Payments on acquired equipment financing	(663)	(834)
Payments on long-term debt	(17,000)	(64,149)
Payments of deferred financing costs		(205)
Excess tax benefit of stock-based compensation awards	288	824
Net cash used in financing activities	(29,909)	(67,660)
Effect of exchange rate fluctuations on cash	(1,152)	3,141
Net increase (decrease) in cash and cash equivalents	29,230	(83,503)
Cash and cash equivalents, beginning of period	146,733	197,858
Cash and cash equivalents, end of period	175,963	114,355
Supplemental disclosures of cash flow information:
Interest	6,738	7,233
Income taxes	$ 23,115	$ 6,213