CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities:
Net income	$ 153,093	$ 141,795
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	76,950	72,717
Amortization of debt issuance costs and discount	16,944	5,689
Share-based compensation	16,960	13,729
(Gain) loss on disposals of property and equipment, net	(504)	292
Loss (earnings) from unconsolidated affiliates	1,454	(2,735)
(Benefit from) provision for deferred income taxes	(15,883)	2,525
Excess income tax benefits on stock option exercises	(145)	(380)
Changes in operating assets and liabilities:
Change in accounts receivable, unbilled services and unearned income	(74,533)	(66,253)
Change in other operating assets and liabilities	7,574	8,348
Net cash provided by operating activities	181,910	175,727
Investing activities:
Acquisition of property, equipment and software	(77,939)	(49,353)
Acquisition of businesses, net of cash acquired	(144,970)	(43,197)
Proceeds from disposition of property and equipment	1,333	1,876
Purchases of equity securities and other investments		(13,365)
Investments in and advances to unconsolidated affiliates, net of payments received	(5,944)	(12,901)
Other	(471)	(2,729)
Net cash used in investing activities	(227,991)	(119,669)
Financing activities:
Proceeds from issuance of debt, net of costs		287,790
Repayment of debt and principal payments on capital lease obligations	(385,807)	(17,304)
Issuance of common stock, net of costs	489,560	1,000
Exercise of stock options	364	350
Repurchase of common stock		(12,920)
Excess income tax benefits on stock option exercises	145	380
Dividends paid to common shareholders		(326,148)
Net cash provided by (used in) financing activities	104,262	(66,852)
Effect of foreign currency exchange rate changes on cash	(16,199)	805
Increase (decrease) in cash and cash equivalents	41,982	(9,989)
Cash and cash equivalents at beginning of period	567,728	516,299
Cash and cash equivalents at end of period	$ 609,710	$ 506,310