Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Cash flows from operating activities
Net income	$ 5,932	$ 20,167
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,924	14,500
Amortization of contract acquisition costs	362	406
Amortization of debt issuance costs	247	171
Imputed interest expense and fair value adjustments to contingent consideration	2,011	20
Provision for doubtful accounts	124	61
(Gain) loss on disposal of assets	18	23
Impairment losses	1,120
Impairment of equity investment	15,632
Gain (adjustment) on bargain purchase of a business	(685)
Deferred income taxes	(972)	(918)
Excess tax benefit from equity-based awards	(227)	(284)
Equity-based compensation expense	3,609	2,041
(Gain) loss on foreign currency derivatives	725	(1,205)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	41,197	28,610
Prepaids and other assets	2,337	(7,187)
Accounts payable and accrued expenses	2,720	10,456
Deferred revenue and other liabilities	(24,687)	8,071
Net cash provided by operating activities	67,387	74,932
Cash flows from investing activities
Proceeds from sale of long-live assets	4	13
Purchases of property, plant and equipment	(7,508)	(12,035)
Payments for contract acquisition costs		(1,021)
Investments in non-marketable equity investments	(2,119)	(1,153)
Acquisitions, net of cash acquired of zero and zero, respectively	(460)
Net cash used in investing activities	(10,083)	(14,196)
Cash flows from financing activities
Proceeds from line of credit	630,800	536,900
Payments on line of credit	(672,300)	(572,200)
Payments on other debt	(1,563)	(1,215)
Payments of contingent consideration and hold back payments to acquisitions	(399)
Payments to noncontrolling interest	(945)	(945)
Tax payments related to issuance of restricted stock units	(1,722)	(687)
Purchase of treasury stock		(11,658)
Net cash provided by financing activities	(46,129)	(49,805)
Effect of exchange rate changes on cash and cash equivalents	(4,018)	280
Increase (decrease) in cash and cash equivalents	7,157	11,211
Cash and cash equivalents, beginning of period	74,437	55,264
Cash and cash equivalents, end of period	81,594	66,475
Supplemental disclosures
Cash paid for interest	4,201	2,127
Cash paid for income taxes	4,143	450
Non-cash investing and financing activities
Acquisition of long lived assets through capital leases	4,048	534
Acquisition of equipment through increase in accounts payable, net	(372)	1,361
Dividends declared but not paid	$ 12,414	$ 10,069