Segments Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation From Segment Totals To Consolidated Abstract
Operating income for reportable segments	$ 126,971				$ 119,505				$ 126,971	$ 119,505	$ 105,443
Non-income tax contingency charge									0	0	(4,132)
CEO transition charges									0	0	(1,317)
Non-operating Charges									(59,983)	(58,689)	(50,744)
Depreciation of corporate assets and amortization									(3,764)	(2,904)	(1,119)
Operating income	13,676	15,863	16,983	16,702	11,367	17,504	14,941	14,100	63,224	57,912	48,131
Interest expense									(4,283)	(4,666)	(5,225)
Interest income									592	1,081	1,201
Other income, net									3,415	5,050	2,106
Income before taxes and equity in net income of associated companies									$ 62,948	$ 59,377	$ 46,213