Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities
Net income	$ 73,923	$ 78,275	$ 53,538
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	41,166	44,889	50,218
Amortization of contract acquisition costs	1,017	1,680	5,267
Amortization of debt issuance costs	808	589	672
Imputed interest expense	904	544	132
Provision for doubtful accounts	368	363	600
Loss (gain) on disposal of assets	305	(415)	(617)
Impairment losses	2,958	230	1,958
Deferred income taxes	2,354	1,658	(3,030)
Excess tax benefit from equity-based awards	(462)	(6,491)	(1,783)
Equity-based compensation expense	13,376	15,856	13,372
(Gain) loss on foreign currency derivatives	414	1,073	(128)
Gain on Newgen legal settlement, net of tax	0	0	(3,542)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	400	(5,789)	(87)
Prepaids and other assets	(25,664)	3,578	17,664
Accounts payable and accrued expenses	(16,301)	(16,502)	19,683
Deferred revenue and other liabilities	11,354	(5,739)	(19,462)
Net cash provided by operating activities	106,920	113,799	134,455
Cash flows from investing activities
Proceeds from sale of long-lived assets	450	2,034	0
Proceeds from grant for property, plant and equipment	110	357	0
Purchases of property, plant and equipment	(40,653)	(38,667)	(26,800)
Payment of contract acquisition costs	0	1,758	0
Investment in deconsolidated subsidiary	0	0	(3,600)
Deposit on pending acquisition	0	3,026	0
Acquisitions, net of cash acquired of $3,741, $14 and $2,202, respectively	(40,839)	(45,871)	(12,798)
Net cash used in investing activities	(80,932)	(86,931)	(43,198)
Cash flows from financing activities
Proceeds from line of credit	1,179,850	678,200	1,257,100
Payments on line of credit	(1,135,850)	(614,200)	(1,257,100)
Proceeds from other debt	8,014	0	0
Payments on other debt	(4,900)	(2,099)	(3,749)
Dividends distributed to noncontrolling interest	(2,205)	(3,548)	(4,140)
Proceeds from exercise of stock options	1,374	14,762	2,792
Excess tax benefit from equity-based awards	462	6,491	1,783
Purchase of treasury stock	(81,243)	(63,693)	(80,295)
Payments of debt issuance costs	(467)	(22)	(2,288)
Net cash provided by (used in) financing activities	(34,965)	15,891	(85,897)
Effect of exchange rate changes on cash and cash equivalents	17,091	(5,773)	4,601
Increase in cash and cash equivalents	8,114	36,986	9,961
Cash and cash equivalents, beginning of period	156,371	119,385	109,424
Cash and cash equivalents, end of period	164,485	156,371	119,385
Supplemental disclosures
Cash paid for interest	4,412	4,013	2,217
Cash paid for income taxes	16,388	24,336	15,593
Non-cash investing and financing activities
Purchases of equipment through financing arrangements	6,100	0	186
Landlord incentives credited to deferred rent	1,723	0	810
Grant income credited to property, plant and equipment	0	110	0
Recognition of asset retirement obligations	$ 0	$ 278	$ 406