Federal and state income taxes Components of Income Tax Expense (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ (14,093)	$ 2,340	$ (4,908)
Current State and Local Tax Expense (Benefit)	9,825	7,795	10,322
Current Income Tax Expense (Benefit)	(4,268)	10,135	5,414
Deferred Federal Income Tax Expense (Benefit)	23,428	1,640	(4,193)
Deferred State and Local Income Tax Expense (Benefit)	7,388	(849)	(3,927)
Deferred Income Tax Expense (Benefit)	30,816	791	(8,120)
Goodwill, Subsequent Recognition of Deferred Tax Asset	1,204	1,204	1,204
Income Tax Expense (Benefit)	$ 27,752	$ 12,130	$ (1,502)