Condensed Consolidating Statement Of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Consolidating Financial Statements [Line Items]
Net cash provided (used) by operating activities			$ 165,019	$ 88,409
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment			(17,514)	(17,584)
Investment in intangible assets			(2,376)	(482)
Proceeds from sales of assets			0	8,360
Acquisitions of real estate			0	(25,263)
Business acquisition, net of cash acquired			0	(1,341)
Contributions to equity method investments			(44,876)	(24,179)
Distributions from equity method investments			4,307	3,700
Purchases of investments, employee benefit plans			(2,140)	(1,430)
Proceeds from sales of investments, employee benefit plans			2,150	1,395
Issuance of mezzanine and other notes receivable			(18,565)	(20,281)
Collections of mezzanine and other notes receivable			630	11,040
Advances to and investment in affiliates			0	0
Divestment in affiliates			0	0
Other items, net			109	60
Net cash used by investing activities			(78,275)	(66,005)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (repayments) borrowings pursuant to revolving credit facilities			(39,974)	52,814
Debt issuance costs			0	(284)
Principal payments on long-term debt			(484)	(836)
Proceeds from transfer of interest in notes receivable			24,237	0
Purchases of treasury stock			(8,887)	(33,958)
Dividends paid			(36,483)	(34,690)
Proceeds from contributions from affiliates			0	0
Distributions to affiliates			0	0
Proceeds from exercise of stock options	$ 3,200	$ 2,600	9,799	6,802
Net cash used by financing activities			(51,792)	(10,152)
Net change in cash and cash equivalents			34,952	12,252
Effect of foreign exchange rate changes on cash and cash equivalents			1,433	260
Cash and cash equivalents at beginning of period			202,463	193,441
Cash and cash equivalents at end of period	238,848	205,953	238,848	205,953
Parent
Condensed Consolidating Financial Statements [Line Items]
Net cash provided (used) by operating activities			101,749	21,358
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment			(14,336)	(12,579)
Investment in intangible assets			(1,647)	(482)
Proceeds from sales of assets				0
Acquisitions of real estate				0
Business acquisition, net of cash acquired				0
Contributions to equity method investments			0	0
Distributions from equity method investments			0	0
Purchases of investments, employee benefit plans			0	0
Proceeds from sales of investments, employee benefit plans			0	0
Issuance of mezzanine and other notes receivable			(9,032)	(5,306)
Collections of mezzanine and other notes receivable			630	11,040
Advances to and investment in affiliates			0	0
Divestment in affiliates			0	0
Other items, net			0	100
Net cash used by investing activities			(24,385)	(7,227)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (repayments) borrowings pursuant to revolving credit facilities			(40,000)	53,000
Debt issuance costs				(284)
Principal payments on long-term debt			0	0
Proceeds from transfer of interest in notes receivable			9,032
Purchases of treasury stock			(8,887)	(33,958)
Dividends paid			(36,483)	(34,690)
Proceeds from contributions from affiliates			0	0
Distributions to affiliates			0	0
Proceeds from exercise of stock options			9,799	6,802
Net cash used by financing activities			(66,539)	(9,130)
Net change in cash and cash equivalents			10,825	5,001
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Cash and cash equivalents at beginning of period			14,696	13,529
Cash and cash equivalents at end of period	25,521	18,530	25,521	18,530
Guarantor Subsidiaries
Condensed Consolidating Financial Statements [Line Items]
Net cash provided (used) by operating activities			44,489	43,956
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment			(2,908)	(4,749)
Investment in intangible assets			(729)	0
Proceeds from sales of assets				0
Acquisitions of real estate				0
Business acquisition, net of cash acquired				0
Contributions to equity method investments			(44,819)	(24,128)
Distributions from equity method investments			2,136	0
Purchases of investments, employee benefit plans			(2,140)	(1,430)
Proceeds from sales of investments, employee benefit plans			2,150	1,395
Issuance of mezzanine and other notes receivable			0	0
Collections of mezzanine and other notes receivable			0	0
Advances to and investment in affiliates			(574)	(25,902)
Divestment in affiliates			2,253	11,858
Other items, net			113	0
Net cash used by investing activities			(44,518)	(42,956)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (repayments) borrowings pursuant to revolving credit facilities			0	0
Debt issuance costs				0
Principal payments on long-term debt			0	(430)
Proceeds from transfer of interest in notes receivable			0
Purchases of treasury stock			0	0
Dividends paid			0	0
Proceeds from contributions from affiliates			0	0
Distributions to affiliates			0	0
Proceeds from exercise of stock options			0	0
Net cash used by financing activities			0	(430)
Net change in cash and cash equivalents			(29)	570
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Cash and cash equivalents at beginning of period			159	19
Cash and cash equivalents at end of period	130	589	130	589
Non-Guarantor Subsidiaries
Condensed Consolidating Financial Statements [Line Items]
Net cash provided (used) by operating activities			19,438	23,752
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment			(270)	(256)
Investment in intangible assets			0	0
Proceeds from sales of assets				8,360
Acquisitions of real estate				(25,263)
Business acquisition, net of cash acquired				(1,341)
Contributions to equity method investments			(57)	(51)
Distributions from equity method investments			2,171	3,700
Purchases of investments, employee benefit plans			0	0
Proceeds from sales of investments, employee benefit plans			0	0
Issuance of mezzanine and other notes receivable			(9,533)	(14,975)
Collections of mezzanine and other notes receivable			0	0
Advances to and investment in affiliates			0	0
Divestment in affiliates			0	0
Other items, net			(4)	(40)
Net cash used by investing activities			(7,693)	(29,866)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (repayments) borrowings pursuant to revolving credit facilities			26	(186)
Debt issuance costs				0
Principal payments on long-term debt			(484)	(406)
Proceeds from transfer of interest in notes receivable			15,205
Purchases of treasury stock			0	0
Dividends paid			(657)	(657)
Proceeds from contributions from affiliates			574	25,902
Distributions to affiliates			(2,253)	(11,858)
Proceeds from exercise of stock options			0	0
Net cash used by financing activities			12,411	12,795
Net change in cash and cash equivalents			24,156	6,681
Effect of foreign exchange rate changes on cash and cash equivalents			1,433	260
Cash and cash equivalents at beginning of period			187,608	179,893
Cash and cash equivalents at end of period	213,197	186,834	213,197	186,834
Eliminations
Condensed Consolidating Financial Statements [Line Items]
Net cash provided (used) by operating activities			(657)	(657)
CASH FLOWS FROM INVESTING ACTIVITIES:
Investment in property and equipment			0	0
Investment in intangible assets			0	0
Proceeds from sales of assets				0
Acquisitions of real estate				0
Business acquisition, net of cash acquired				0
Contributions to equity method investments			0	0
Distributions from equity method investments			0	0
Purchases of investments, employee benefit plans			0	0
Proceeds from sales of investments, employee benefit plans			0	0
Issuance of mezzanine and other notes receivable			0	0
Collections of mezzanine and other notes receivable			0	0
Advances to and investment in affiliates			574	25,902
Divestment in affiliates			(2,253)	(11,858)
Other items, net			0	0
Net cash used by investing activities			(1,679)	14,044
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (repayments) borrowings pursuant to revolving credit facilities			0	0
Debt issuance costs				0
Principal payments on long-term debt			0	0
Proceeds from transfer of interest in notes receivable			0
Purchases of treasury stock			0	0
Dividends paid			657	657
Proceeds from contributions from affiliates			(574)	(25,902)
Distributions to affiliates			2,253	11,858
Proceeds from exercise of stock options			0	0
Net cash used by financing activities			2,336	(13,387)
Net change in cash and cash equivalents			0	0
Effect of foreign exchange rate changes on cash and cash equivalents			0	0
Cash and cash equivalents at beginning of period			0	0
Cash and cash equivalents at end of period	$ 0	$ 0	$ 0	$ 0