Income Taxes Income Tax Rate Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate	$ 33,451	$ 37,565	$ 32,506
Income Tax Reconciliation, State and Local Income Taxes	1,554	981	(213)
Income Tax Reconciliation, Tax Exempt Income	(48)	(104)	(243)
Income Tax Reconciliation, Tax Contingencies	(616)	(1,159)	(1,377)
Income Tax Reconciliation, Other Adjustments	(307)	115	(16)
Income Tax Expense (Benefit)	$ 34,034	$ 37,398	$ 30,657