Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net income	$ 22,829	$ 18,172
Adjustments for items not affecting cash:
Depreciation and amortization expenses	19,293	17,115
Stock option compensation expense	1,187	1,539
Equity-classified share unit expense	1,786	2,368
Deferred income tax expense	1,331	1,057
Unrealized foreign exchange (gain) loss	782	(48)
Gain on disposition of property, plant and equipment	(47)	(149)
Amortization of debt issuance costs	756	934
Gain on contingent consideration from equity investment	(1,700)
Amortization of right-of-use assets	3,343	2,976
Other, net	1,282	534
Net changes in operating assets and liabilities	(46,710)	27,405
Net cash provided by operating activities	4,132	71,903
Investing activities:
Property, plant and equipment additions	(3,495)	(2,801)
Intangible asset additions	(7,220)	(5,625)
Proceeds on disposition of property, plant and equipment	333	262
Distribution from equity investment	4,212
Proceeds on contingent consideration from equity investment	1,700
Other, net	(2,804)
Net cash used in investing activities	(7,274)	(8,164)
Financing activities:
Share repurchase	(53,170)
Dividends paid to stockholders	(21,905)	(19,568)
Issuances of share capital	7,054	1,628
Payment of withholding taxes on issuance of shares	(2,984)	(2,047)
Proceeds from short-term debt	29,069	6,741
Repayment of short-term debt		(17,946)
Repayment of long-term debt	(4,236)	(12,235)
Repayment of finance lease obligations	(2,189)	(1,269)
Net cash provided by (used in) financing activities	(48,361)	(44,696)
Effect of changes in foreign currency rates on cash, cash equivalents, and restricted cash	(12,828)	(1,376)
Increase (decrease)	(64,331)	17,667
Beginning of period	420,256	305,567
Cash, cash equivalents, and restricted cash, end of period	$ 355,925	$ 323,234