Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income	$ 170,358	$ 149,140	$ 121,506
Adjustments for items not affecting cash:
Depreciation and amortization expenses	74,921	70,501	66,614
Stock option compensation expense	5,853	4,697	8,252
Equity-classified share unit expense	9,897	8,047	11,256
Share-based continuing employment costs	802
Deferred income tax expense	9,152	8,826	6,239
Unrealized foreign exchange (gain) loss	2,453	(3,058)	951
Gain on disposition of property, plant and equipment	(1,559)	(1,107)	(2,731)
Amortization of debt issuance costs	3,123	4,086	4,995
Gain on disposition of equity investment			(4,935)
Amortization of right-of-use assets	12,240	12,280
Gain on contingent consideration from equity investment	(1,700)
Other, net	1,466	2,779	(2,317)
Net changes in operating assets and liabilities	(29,134)	76,602	(65,550)
Net cash provided by operating activities	257,872	332,793	144,280
Investing activities:
Acquisition of Rouse, net of cash acquired	(250,039)
Property, plant and equipment additions	(14,263)	(13,589)	(16,860)
Proceeds on disposition of property, plant and equipment	16,385	5,929	10,586
Intangible asset additions	(28,873)	(27,415)	(26,152)
Issuance of loans receivable	(9,071)
Repayment of loans receivable	3,227
Distribution from equity investment	4,212
Proceeds on contingent consideration from equity investment	1,700		6,147
Other, net		(982)	(4,674)
Net cash used in investing activities	(276,722)	(36,057)	(30,953)
Financing activities:
Share repurchase	(53,170)	(42,012)
Dividends paid to stockholders	(91,737)	(82,535)	(75,678)
Dividends paid to NCI	(320)
Proceeds from exercise of options and share option plans	44,128	41,094	28,524
Payment of withholding taxes on issuance of shares	(6,656)	(5,260)	(3,901)
Proceeds from short-term debt	50,799	13,169	19,715
Repayment of short-term debt	(29,368)	(28,684)	(6,628)
Repayment of long-term debt	(13,711)	(76,282)	(91,013)
Debt issue costs	(2,038)
Repayment of finance lease obligations	(9,388)	(6,708)	(3,950)
Other, net			(1,176)
Net cash used in financing activities	(111,461)	(187,218)	(134,107)
Effect of changes in foreign currency rates on cash, cash equivalents, and restricted cash	16,950	5,171	(4,769)
Increase	(113,361)	114,689	(25,549)
Beginning of period	420,256	305,567	331,116
Cash, cash equivalents, and restricted cash, end of period	$ 306,895	$ 420,256	$ 305,567