Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income	$ 12,229	$ 35,961
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	34,735	30,758
Amortization of contract acquisition costs	758	809
Amortization of debt issuance costs	494	341
Imputed interest expense and fair value adjustments to contingent consideration	5,128	31
Provision for doubtful accounts	257	313
(Gain) loss on disposal of assets	35	12
Gain on sale of business		(30)
Impairment losses	1,120
Impairment of equity investment	15,632
Gain (adjustment) on bargain purchase of a business	(685)
Non-cash loss on assets held-for-sale	2,000	3,178
Deferred income taxes	(2,327)	5,901
Excess tax benefit from equity-based awards	(274)	(703)
Equity-based compensation expense	6,183	4,836
(Gain) loss on foreign currency derivatives	149	575
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	65,698	26,669
Prepaids and other assets	(37)	(22,656)
Accounts payable and accrued expenses	(9,943)	27,281
Deferred revenue and other liabilities	(26,446)	12,179
Net cash provided by operating activities	104,706	125,455
Cash flows from investing activities
Proceeds from sale of long-live assets	8	22
Purchases of property, plant and equipment	(16,883)	(29,589)
Proceeds from sale of business		250
Investments in non-marketable equity investments	(2,119)	(1,384)
Acquisitions, net of cash acquired of $4.5 million and zero, respectively	(2,002)	(79,574)
Net cash used in investing activities	(20,996)	(110,275)
Cash flows from financing activities
Proceeds from line of credit	1,093,800	1,151,700
Payments on line of credit	(1,148,800)	(1,112,000)
Payments on other debt	(2,841)	(3,025)
Payments of contingent consideration and hold back payments to acquisitions	(785)	(435)
Dividends paid to shareholders	(12,414)	(10,069)
Payments to noncontrolling interest	(1,125)	(1,800)
Proceeds from exercise of stock options		2,150
Tax payments related to issuance of restricted stock units	(2,287)	(1,876)
Payments of debt issuance costs	(35)	(3)
Purchase of treasury stock		(18,328)
Net cash (used in) provided by financing activities	(74,487)	6,314
Effect of exchange rate changes on cash and cash equivalents	(12,400)	1,152
Increase (decrease) in cash and cash equivalents	(3,177)	22,646
Cash and cash equivalents, beginning of period	74,437	55,264
Cash and cash equivalents, end of period	71,260	77,910
Supplemental disclosures
Cash paid for interest	8,593	4,857
Cash paid for income taxes	20,213	5,905
Non-cash investing and financing activities
Acquisition of long lived assets through capital leases	7,539	874
Acquisition of equipment through increase in accounts payable, net	$ 248	$ (1,274)