Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 17,207	$ 10,433
Adjustments for items not affecting cash:
Depreciation and amortization expenses	16,191	10,338
Stock option compensation expense	2,343	1,311
Equity-classified PSU expense	3,035	1,012
Amortization of debt issuance costs	1,066	445
Other, net	2,131	(1,042)
Net changes in operating assets and liabilities	25,265	112,045
Net cash provided by operating activities	67,238	134,542
Investing activities:
Property, plant and equipment additions	(2,564)	(1,863)
Intangible asset additions	(7,034)	(5,664)
Proceeds on disposition of property, plant and equipment	1,066	1,505
Other, net	(4,674)
Net cash used in investing activities	(13,206)	(6,022)
Financing activities:
Dividends paid to stockholders	(18,245)	(18,160)
Dividends paid to NCI		(41)
Issuances of share capital	4,313	3,412
Proceeds from short-term debt	308	1,219
Repayment of short-term debt	(1,754)	(1,009)
Repayment of long-term debt	(29,237)
Repayment of finance lease obligations	(802)	(438)
Other, net		(48)
Net cash used in financing activities	(45,417)	(15,065)
Effect of changes in foreign currency rates on cash, cash equivalents, and restricted cash	1,627	3,336
Increase	10,242	116,791
Beginning of period	331,116	758,089
Cash, cash equivalents, and restricted cash, end of period	$ 341,358	$ 874,880