Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating activities
Net income	$ 156,128	$ 109,563
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	9,831	8,477
Stock-based compensation	14,287	15,622
Provision for losses on accounts receivable	16,788	13,600
Amortization of deferred financing costs	1,596	1,351
Amortization of intangible assets	23,044	13,969
Amortization of premium on receivables	2,449	2,450
Deferred income taxes	2,501	(863)
Loss on early extinguishment of debt		2,669
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash	3,576	4,942
Accounts receivable	(178,715)	(140,491)
Prepaid expenses and other current assets	(4,352)	14,732
Other assets	(45,291)	(81)
Excess tax benefits related to stock-based compensation	(23,177)	(8,170)
Accounts payable, accrued expenses and customer deposits	54,466	32,747
Net cash provided by operating activities	33,131	70,517
Investing activities
Acquisitions, net of cash acquired	(189,819)	(21,933)
Purchases of property and equipment	(13,634)	(8,408)
Net cash used in investing activities	(203,453)	(30,341)
Financing activities
Excess tax benefits related to stock-based compensation	23,177	8,170
Borrowings on securitization facility, net	75,000	6,000
Deferred financing costs paid	(796)	(7,839)
Proceeds from issuance of common stock	21,391	5,066
Principal payments on notes payable	(23,492)	(335,215)
Borrowings on notes payable		300,000
Principal payments on revolver	(250,000)
Borrowings from revolver	330,000
Borrowings on swing line of credit, net	1,000
Other	(129)	(179)
Net cash provided by (used in) financing activities	176,151	(23,997)
Effect of foreign currency exchange rates on cash	9,073	6,301
Net increase in cash and cash equivalents	14,902	22,480
Cash and cash equivalents, beginning of period	285,159	114,804
Cash and cash equivalents, end of period	300,061	137,284
Supplemental cash flow information
Cash paid for interest	10,858	11,213
Cash paid for income taxes	$ 29,428	$ 35,171