Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Loss Carryforwards [Line Items]
Exercise of stock options and vesting of stock awards, amount	$ 242,000	$ 108,000	$ 28,000
Annual limitation on deferred tax asset	313,000
Deferred tax assets, state operating loss carryforwards	2,100,000	2,000,000
Valuation allowance	4,167,000	1,964,000
Federal corporate tax rate	35.00%
Tax credits	6,669,000	798,000	554,000
Investment in low-income housing	4,500,000	7,600,000	8,400,000
Unrecognized tax benefits	773,000	751,000	1,198,000
Unrecognized tax benefits, accrued interest and penalties	80,000	113,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	38,400,000	40,000,000
First Shares Inc
Operating Loss Carryforwards [Line Items]
Deferred tax assets, federal operating loss carryforwards	1,600,000
First Shares Inc | Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	4,600,000
Valuation Allowance, Operating Loss Carryforwards | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Valuation allowance	2,000,000	2,000,000
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Valuation allowance	2,200,000
Historic Rehabilitation Credit
Operating Loss Carryforwards [Line Items]
Tax credits	5,800,000
Low-income Housing
Operating Loss Carryforwards [Line Items]
Tax credits	798,000	798,000	554,000
Tax credits, expected utilization, 2013	798,000
Tax credits, expected utilization, 2014	798,000
Tax credits, expected utilization, 2015	755,000
Tax credits, expected utilization, 2016	581,000
Tax credits, expected utilization, 2017	581,000
Tax credits, expected utilization, 2018	581,000
Tax credits, expected utilization, 2019	581,000
Tax credits, expected utilization, 2020	241,000
Illinois | 2007 and 2008 | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Income tax refund	29,000
Illinois | 2009, 2010 and 2011 | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Income tax refund	$ 151,000