Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities
Net income	$ 21,303	$ 18,603
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	13,170	10,555
Amortization of contract acquisition costs	358	255
Amortization of debt issuance costs	170	175
Imputed interest expense and fair value adjustments to contingent consideration	200	346
Provision for doubtful accounts	113	76
Gain on disposal of assets	0	(107)
Deferred income taxes	990	3,975
Excess tax benefit from equity-based awards	(788)	(800)
Equity-based compensation expense	3,160	3,191
Gain on foreign currency derivatives	(634)	(433)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(8,092)	5,012
Prepaids and other assets	1,618	(7,630)
Accounts payable and accrued expenses	(10,817)	(19,399)
Deferred revenue and other liabilities	(7,214)	(7,325)
Net cash provided by operating activities	13,537	6,494
Cash flows from investing activities
Proceeds from sale of property, plant and equipment	135	0
Purchases of property, plant and equipment, net of acquisitions	(15,095)	(4,105)
Acquisitions, net of cash acquired of $812 and zero, respectively	(8,160)	0
Net cash used in investing activities	(23,120)	(4,105)
Cash flows from financing activities
Proceeds from line of credit	632,900	366,950
Payments on line of credit	(632,900)	(359,950)
Proceeds from other debt	0	3,709
Payments on other debt	(1,525)	(1,338)
Payments of purchase price payables	(2,189)	0
Dividends distributed to noncontrolling interest	(990)	(1,109)
Proceeds from exercise of stock options	12	539
Excess tax benefit from equity-based awards	788	800
Purchase of treasury stock	(20,466)	(9,850)
Net cash used in financing activities	(24,370)	(249)
Effect of exchange rate changes on cash and cash equivalents	(3,687)	3,926
(Decrease) increase in cash and cash equivalents	(37,640)	6,066
Cash and cash equivalents, beginning of period	158,017	164,485
Cash and cash equivalents, end of period	120,377	170,551
Supplemental disclosures
Cash paid for interest	982	1,048
Cash paid for income taxes	2,834	1,751
Non-cash investing and financing activities
Acquisition of equipment through increase in accounts payable	941	0
Contract acquisition costs credited to accounts receivable	$ 1,000	$ 0