Segments Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation From Segment Totals To Consolidated Abstract
Operating income for reportable segments	$ 142,500				$ 126,971				$ 142,500	$ 126,971	$ 124,274
Non-operating Charges									(67,145)	(59,983)	(58,689)
Depreciation of corporate assets and amortization									(4,112)	(3,764)	(2,904)
Operating income	15,232	18,807	19,793	17,411	13,676	15,863	16,983	16,702	71,243	63,224	57,912
Interest expense									(2,922)	(4,283)	(4,666)
Interest income									986	592	1,081
Other income, net									3,519	3,415	5,050
Income before taxes and equity in net income of associated companies									$ 72,826	$ 62,948	$ 59,377