Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 47,305	$ 44,993	$ 135,795	$ 125,171
Other comprehensive income (loss), net of tax	6,198	14,601	(26,675)	30,927
Comprehensive income	$ 53,503	$ 59,594	$ 109,120	$ 156,098