Income Taxes Income Taxes-Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013 state	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Examination [Line Items]
Effective Income Tax Rate Reconciliation, Tax Credit, Amount		$ 1,100,000	$ 1,100,000	$ 1,000,000
Number of states the company files income tax returns in		9
Unrecognized tax benefits		1,257,000	1,148,000	1,057,000	4,003,000
Unrecognized tax benefits that would impact effective tax rate		845,000	771,000	741,000
Reduction in unrecognized tax benefit that is reasonably possible due to a lapse of statute of limitations	300,000
income tax benefit low income housing tax credits		200,000	200,000
investments low income housing tax credits		4,200,000	5,100,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Impairment Losses		0
Capital Commitments Tax Credits		600,000
duration of unrecognized tax benefits	12 months
State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
State valuation allowance		$ 0