Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net income	$ 52,785	$ 61,030
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,040	34,828
Amortization of contract acquisition costs	763	1,448
Amortization of debt issuance costs	531	435
Imputed interest expense	600	649
Provision for doubtful accounts	490	301
Loss (gain) on disposal of assets	180	(351)
Impairment losses	2,958	230
Deferred income taxes	2,134	5,582
Excess tax benefit from equity-based awards	(1,005)	(5,276)
Equity-based compensation expense	10,310	11,563
(Gain) loss on foreign currency derivatives	(574)	966
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	1,091	(26,332)
Prepaids and other assets	(30,893)	(8,939)
Accounts payable and accrued expenses	(15,696)	(28,302)
Deferred revenue and other liabilities	8,697	(8,330)
Net cash provided by operating activities	63,411	39,502
Cash flows from investing activities
Proceeds from grant for property, plant and equipment	110	2,197
Proceeds from sale of long-lived assets	450	0
Purchases of property, plant and equipment, net of acquisitions	(33,259)	(21,166)
Payment of contract acquisition costs	0	738
Acquisitions, net of cash acquired of $1,373 and $14, respectively	(4,809)	(45,787)
Net cash used in investing activities	(37,508)	(65,494)
Cash flows from financing activities
Proceeds from line of credit	857,650	556,800
Payments on line of credit	(833,650)	(426,500)
Proceeds from other debt	8,014	0
Payments on other debt	(2,783)	(1,646)
Dividends distributed to noncontrolling interest	(1,440)	(2,783)
Proceeds from exercise of stock options	1,135	8,528
Excess tax benefit from equity-based awards	1,005	5,276
Purchase of treasury stock	(55,211)	(58,367)
Payments of debt issuance costs	(432)	(22)
Net cash (used in) provided by financing activities	(25,712)	81,286
Effect of exchange rate changes on cash and cash equivalents	13,815	(4,870)
Increase in cash and cash equivalents	14,006	50,424
Cash and cash equivalents, beginning of period	156,371	119,385
Cash and cash equivalents, end of period	170,377	169,809
Supplemental disclosures
Cash paid for interest	3,168	2,908
Cash paid for income taxes	13,213	16,710
Non-cash investing and financing activities
Purchases of equipment through financing arrangements	6,100	0
Landlord incentives credited to deferred rent	$ 1,723	$ 0