Income Taxes Income Tax Expense Detail (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Current Federal Tax Expense (Benefit)	$ 38,148	$ 20,460	$ 40,165
Current State and Local Tax Expense (Benefit)	1,636	2,195	(1,068)
Current Income Tax Expense (Benefit)	39,784	22,655	39,097
Deferred Federal Income Tax Expense (Benefit)	(5,890)	16,587	(7,804)
Deferred State and Local Income Tax Expense (Benefit)	140	(1,844)	(636)
Deferred Income Tax Expense (Benefit)	(5,750)	14,743	(8,440)
Income Tax Expense (Benefit)	$ 34,034	$ 37,398	$ 30,657