Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes [Abstract]
Tax provision at Federal statutory rate	$ 52,994	$ (1,072)	$ (45,042)
Tax provision at Federal statutory rate, effective tax rate	35.00%	35.00%	35.00%
State income taxes, net of Federal income tax benefit	9,477	(1,641)	(6,175)
State income taxes, net of Federal income tax benefit, tax rate	6.30%	53.50%	4.80%
Interest on obligations of state and political subdivisions, which are exempt from Federal taxation	(1,476)	(299)	(267)
Interest on obligations of state and political subdivisions, which are exempt from Federal taxation, tax rate	(1.00%)	9.80%	0.20%
Low income housing and other tax credits	(10,087)	(11,220)	(10,575)
Low income housing and other tax credits, tax rate	(6.60%)	366.20%	8.20%
Income tax expense, Other, net	353	(397)	147
Income tax rate, Other, net	0.20%	13.00%	(0.10%)
Total income tax (benefit)/expense	$ 51,261	$ (14,629)	$ (61,912)
Total income tax (benefit)/expense, tax rate	33.90%	477.50%	48.10%