Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities
Net income	$ 31,325	$ 23,065
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	21,818	20,345
Amortization of contract acquisition costs	506	508
Amortization of debt issuance costs	319	347
Imputed interest expense	670	373
Provision for doubtful accounts	478	48
Loss (gain) on disposal of assets	(106)	137
Impairment losses	1,205	2,797
Deferred income taxes	2,697	(8,097)
Excess tax benefit from equity-based awards	(1,046)	(1,136)
Equity-based compensation expense	6,577	6,845
(Gain) loss on foreign currency derivatives	(2,768)	(963)
Loss on deconsolidation of subsidiary, net of cash of $897 and zero, respectively	2,758	0
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(2,804)	1,095
Prepaids and other assets	1,044	(11,979)
Accounts payable and accrued expenses	(14,151)	13,453
Deferred revenue and other liabilities	(8,311)	1,819
Net cash provided by operating activities	40,211	48,657
Cash flows from investing activities
Proceeds from grant for property, plant and equipment	0	110
Proceeds from sale of long-lived assets	0	225
Purchases of property, plant and equipment, net of acquisitions	(13,660)	(17,478)
Acquisitions, net of cash acquired of $0 and $1,373, respectively	(1,652)	(4,809)
Net cash used in investing activities	(15,312)	(21,952)
Cash flows from financing activities
Proceeds from line of credit	681,550	515,950
Payments on line of credit	(679,550)	(501,950)
Proceeds from other debt	3,709	6,821
Payments on other debt	(2,661)	(1,390)
Dividends distributed to noncontrolling interest	(2,385)	(720)
Proceeds from exercise of stock options	856	770
Excess tax benefit from equity-based awards	1,046	1,136
Purchase of treasury stock	(31,001)	(40,732)
Payments of debt issuance costs	(1,732)	(432)
Net cash used in financing activities	(30,168)	(20,547)
Effect of exchange rate changes on cash and cash equivalents	(8,593)	8,049
(Decrease) increase in cash and cash equivalents	(13,862)	14,207
Cash and cash equivalents, beginning of period	164,485	156,371
Cash and cash equivalents, end of period	150,623	170,578
Supplemental disclosures
Cash paid for interest	2,226	1,706
Cash paid for income taxes	8,913	8,546
Non-cash investing and financing activities
Purchases of equipment through financing arrangements	0	6,100
Grant income credited to property, plant and eqiupment	0	110
Landlord incentives credited to deferred rent	$ 511	$ 604