Condensed Consolidating Financial Statements Condensed Consolidating Statement Of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net cash provided (used) by operating activities	$ 1,874	$ 4,412
Investment in property and equipment	(13,645)	(3,129)
Equity method investments	(1,000)	(2,600)
Issuance of notes receivable	(1,729)	(3,719)
Collections of notes receivable	19	151
Purchases of investments, employee benefit plans	(1,242)	(743)
Proceeds from sales of investments, employee benefit plans	3,882	8,652
Other items, net	(101)	(108)
Net cash used in investing activities	(13,816)	(1,496)
Repayments of long-term debt	(2,046)	(166)
Purchase of treasury stock	(3,634)	(14,854)
Dividends paid	(503)	(10,713)
Excess tax benefits from stock-based compensation	952	422
Proceeds from exercise of stock options	5,367	389
Net cash provided by (used) in financing activities	18,136	(19,022)
Net change in cash and cash equivalents	6,194	(16,106)
Effect of foreign exchange rate changes on cash and cash equivalents	(146)	361
Cash and cash equivalents at beginning of period	134,177	107,057
Cash and cash equivalents at end of period	140,225	91,312
Parent [Member]
Net cash provided (used) by operating activities	(17,180)	5,388
Investment in property and equipment	(2,328)	(1,354)
Equity method investments	0	0
Issuance of notes receivable	0	(3,136)
Collections of notes receivable	19	44
Purchases of investments, employee benefit plans	0	0
Proceeds from sales of investments, employee benefit plans	0	0
Advances to and investments in affiliates	(1,000)	0
Other items, net	(101)	(108)
Net cash used in investing activities	(3,410)	(4,554)
Net borrowings pursuant to revolving credit facilities	18,000	5,900
Repayments of long-term debt	(1,875)	0
Purchase of treasury stock	(3,634)	(14,854)
Dividends paid	(503)	(10,713)
Excess tax benefits from stock-based compensation	0	0
Proceeds from contributions from affiliates	0	0
Proceeds from exercise of stock options	5,367	389
Net cash provided by (used) in financing activities	17,355	(19,278)
Net change in cash and cash equivalents	(3,235)	(18,444)
Effect of foreign exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	8,420	23,370
Cash and cash equivalents at end of period	5,185	4,926
Guarantor Subsidiaries [Member]
Net cash provided (used) by operating activities	9,216	(3,265)
Investment in property and equipment	(11,237)	(1,688)
Equity method investments	0	0
Issuance of notes receivable	(1,484)	(583)
Collections of notes receivable	0	107
Purchases of investments, employee benefit plans	(1,242)	(743)
Proceeds from sales of investments, employee benefit plans	3,882	8,652
Advances to and investments in affiliates	0	(2,623)
Other items, net	0	0
Net cash used in investing activities	(10,081)	3,122
Net borrowings pursuant to revolving credit facilities	0	0
Repayments of long-term debt	(166)	(161)
Purchase of treasury stock	0	0
Dividends paid	0	0
Excess tax benefits from stock-based compensation	952	422
Proceeds from contributions from affiliates	0	0
Proceeds from exercise of stock options	0	0
Net cash provided by (used) in financing activities	786	261
Net change in cash and cash equivalents	(79)	118
Effect of foreign exchange rate changes on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	407	432
Cash and cash equivalents at end of period	328	550
Non-Guarantor Subsidiaries [Member]
Net cash provided (used) by operating activities	9,838	2,289
Investment in property and equipment	(80)	(87)
Equity method investments	(1,000)	(2,600)
Issuance of notes receivable	(245)	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
Advances to and investments in affiliates	0	0
Other items, net	0	0
Net cash used in investing activities	(1,325)	(2,687)
Net borrowings pursuant to revolving credit facilities	0	0
Repayments of long-term debt	(5)	(5)
Purchase of treasury stock	0	0
Dividends paid	0	0
Excess tax benefits from stock-based compensation	0	0
Proceeds from contributions from affiliates	1,000	2,623
Proceeds from exercise of stock options	0	0
Net cash provided by (used) in financing activities	995	2,618
Net change in cash and cash equivalents	9,508	2,220
Effect of foreign exchange rate changes on cash and cash equivalents	(146)	361
Cash and cash equivalents at beginning of period	125,350	83,255
Cash and cash equivalents at end of period	134,712	85,836
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
Advances to and investments in affiliates	1,000	2,623
Other items, net	0	0
Net cash used in investing activities	1,000	2,623
Net borrowings pursuant to revolving credit facilities	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
Proceeds from contributions from affiliates	(1,000)	(2,623)
Proceeds from exercise of stock options	0	0
Net cash provided by (used) in financing activities	(1,000)	(2,623)
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	1,874	4,412
Investment in property and equipment	(13,645)	(3,129)
Equity method investments	(1,000)	(2,600)
Issuance of notes receivable	(1,729)	(3,719)
Collections of notes receivable	19	151
Purchases of investments, employee benefit plans	(1,242)	(743)
Proceeds from sales of investments, employee benefit plans	3,882	8,652
Advances to and investments in affiliates	0	0
Other items, net	(101)	(108)
Net cash used in investing activities	(13,816)	(1,496)
Net borrowings pursuant to revolving credit facilities	18,000	5,900
Repayments of long-term debt	(2,046)	(166)
Purchase of treasury stock	(3,634)	(14,854)
Dividends paid	(503)	(10,713)
Excess tax benefits from stock-based compensation	952	422
Proceeds from contributions from affiliates	0	0
Proceeds from exercise of stock options	5,367	389
Net cash provided by (used) in financing activities	18,136	(19,022)
Net change in cash and cash equivalents	6,194	(16,106)
Effect of foreign exchange rate changes on cash and cash equivalents	(146)	361
Cash and cash equivalents at beginning of period	134,177	107,057
Cash and cash equivalents at end of period	$ 140,225	$ 91,312