Income Taxes Schedule of Components of Income Tax Expense (Benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:
Federal	$ 115,150	$ 110,825	$ 97,887
State	20,869	19,693	14,435
Foreign	23,906	13,202	3,883
Current income tax expense, total	159,925	143,720	116,205
Deferred:
Federal	6,225	5,824	8,376
State	(550)	(647)	919
Foreign	(1,396)	(955)	7
Deferred income tax expense, total	4,279	4,222	9,302
Provision for income taxes	$ 164,204	$ 147,942	$ 125,507