Income Taxes (Income Tax Expense (Benefit)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes
Federal, Current	$ 18,667	$ 13,697	$ 10,160
Federal, Deferred	9,136	9,788	6,423
Federal, Total	27,803	23,485	16,583
State, Current	4,349	3,323	2,386
State, Deferred	2,331	2,498	1,639
State, Total	6,680	5,821	4,025
Foreign, Current	(953)	1,340	817
Foreign, Deferred	(344)	(1,049)	(4,289)
Foreign, Total	(1,297)	291	(3,472)
Total federal, state and foreign income tax expense	$ 33,186	$ 29,597	$ 17,136