Condensed Consolidating Financial Statements Condensed Consolidating Statement Of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net cash provided (used) by operating activities	$ 121,276	$ 105,893
Investment in property and equipment	(12,525)	(8,129)
Equity method investments	(9,454)	(3,600)
Issuance of notes receivable	(7,305)	(4,320)
Collections of notes receivable	326	15
Purchases of investments, employee benefit plans	(1,191)	(1,051)
Proceeds from sales of investments, employee benefit plans	10,909	566
Other items, net	(322)	(312)
Net cash provided (used) by investing activities	(19,562)	(16,831)
Net borrowings (repayments) pursuant to revolving credit facilities	16,725	(200)
Proceeds from issuance of long-term debt	543,500	75
Repayments of long-term debt	(502)	(74)
Purchase of treasury stock	(22,227)	(24,796)
Dividends paid	(632,751)	(32,923)
Excess tax benefits from stock-based compensation	793	1,108
Debt issuance costs	(4,753)	(2,356)
Proceeds from exercise of stock options	4,695	3,726
Net cash provided (used) by financing activities	(94,520)	(55,440)
Net change in cash and cash equivalents	7,194	33,622
Effect of foreign exchange rate changes on cash and cash equivalents	813	(147)
Cash and cash equivalents at beginning of period	107,057	91,259
Cash and cash equivalents at end of period	115,064	124,734
Parent [Member]
Net cash provided (used) by operating activities	87,073	96,333
Investment in property and equipment	(7,126)	(2,460)
Equity method investments	0	0
Issuance of notes receivable	(4,237)	(1,404)
Collections of notes receivable	110	0
Purchases of investments, employee benefit plans	0	0
Proceeds from sales of investments, employee benefit plans	0	0
Other items, net	(322)	(289)
Net cash provided (used) by investing activities	(11,575)	(4,153)
Net borrowings (repayments) pursuant to revolving credit facilities	16,725	(200)
Proceeds from issuance of long-term debt	543,500	0
Repayments of long-term debt	0	0
Purchase of treasury stock	(22,227)	(24,796)
Dividends paid	(632,751)	(32,923)
Excess tax benefits from stock-based compensation	183	38
Debt issuance costs	(4,753)	(2,356)
Proceeds from exercise of stock options	4,695	3,726
Net cash provided (used) by financing activities	(94,628)	(56,511)
Net change in cash and cash equivalents	(19,130)	35,669
Effect of foreign exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	23,370	4,849
Cash and cash equivalents at end of period	4,240	40,518
Guarantor Subsidiaries [Member]
Net cash provided (used) by operating activities	(1,928)	(10,502)
Investment in property and equipment	(5,217)	(5,395)
Equity method investments	0	0
Issuance of notes receivable	(3,068)	(2,916)
Collections of notes receivable	216	15
Purchases of investments, employee benefit plans	(1,191)	(1,051)
Proceeds from sales of investments, employee benefit plans	10,909	566
Other items, net	0	(5)
Net cash provided (used) by investing activities	1,649	(8,786)
Net borrowings (repayments) pursuant to revolving credit facilities	0	0
Proceeds from issuance of long-term debt	0	0
Repayments of long-term debt	(488)	(55)
Purchase of treasury stock	0	0
Dividends paid	0	0
Excess tax benefits from stock-based compensation	610	1,070
Debt issuance costs	0	0
Proceeds from exercise of stock options	0	0
Net cash provided (used) by financing activities	122	1,015
Net change in cash and cash equivalents	(157)	(18,273)
Effect of foreign exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	432	18,659
Cash and cash equivalents at end of period	275	386
Non-Guarantor Subsidiaries [Member]
Net cash provided (used) by operating activities	36,131	20,062
Investment in property and equipment	(182)	(274)
Equity method investments	(9,454)	(3,600)
Issuance of notes receivable	0	0
Collections of notes receivable	0	0
Purchases of investments, employee benefit plans	0	0
Proceeds from sales of investments, employee benefit plans	0	0
Other items, net	0	(18)
Net cash provided (used) by investing activities	(9,636)	(3,892)
Net borrowings (repayments) pursuant to revolving credit facilities	0	0
Proceeds from issuance of long-term debt	0	75
Repayments of long-term debt	(14)	(19)
Purchase of treasury stock	0	0
Dividends paid	0	0
Excess tax benefits from stock-based compensation	0	0
Debt issuance costs	0	0
Proceeds from exercise of stock options	0	0
Net cash provided (used) by financing activities	(14)	56
Net change in cash and cash equivalents	26,481	16,226
Effect of foreign exchange rate changes on cash and cash equivalents	813	(147)
Cash and cash equivalents at beginning of period	83,255	67,751
Cash and cash equivalents at end of period	110,549	83,830
Eliminations [Member]
Net cash provided (used) by operating activities	0	0
Investment in property and equipment	0	0
Equity method investments	0	0
Issuance of notes receivable	0	0
Collections of notes receivable	0	0
Purchases of investments, employee benefit plans	0	0
Proceeds from sales of investments, employee benefit plans	0	0
Other items, net	0	0
Net cash provided (used) by investing activities	0	0
Net borrowings (repayments) pursuant to revolving credit facilities	0	0
Proceeds from issuance of long-term debt	0	0
Repayments of long-term debt	0	0
Purchase of treasury stock	0	0
Dividends paid	0	0
Excess tax benefits from stock-based compensation	0	0
Debt issuance costs	0	0
Proceeds from exercise of stock options	0	0
Net cash provided (used) by financing activities	0	0
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
Consolidated [Member]
Net cash provided (used) by operating activities	121,276	105,893
Investment in property and equipment	(12,525)	(8,129)
Equity method investments	(9,454)	(3,600)
Issuance of notes receivable	(7,305)	(4,320)
Collections of notes receivable	326	15
Purchases of investments, employee benefit plans	(1,191)	(1,051)
Proceeds from sales of investments, employee benefit plans	10,909	566
Other items, net	(322)	(312)
Net cash provided (used) by investing activities	(19,562)	(16,831)
Net borrowings (repayments) pursuant to revolving credit facilities	16,725	(200)
Proceeds from issuance of long-term debt	543,500	75
Repayments of long-term debt	(502)	(74)
Purchase of treasury stock	(22,227)	(24,796)
Dividends paid	(632,751)	(32,923)
Excess tax benefits from stock-based compensation	793	1,108
Debt issuance costs	(4,753)	(2,356)
Proceeds from exercise of stock options	4,695	3,726
Net cash provided (used) by financing activities	(94,520)	(55,440)
Net change in cash and cash equivalents	7,194	33,622
Effect of foreign exchange rate changes on cash and cash equivalents	813	(147)
Cash and cash equivalents at beginning of period	107,057	91,259
Cash and cash equivalents at end of period	$ 115,064	$ 124,734