Termination Charges (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Salary and Benefits Continuation AND Special Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Termination benefits included in liabilities	$ 1,000,000
2014 Plan Year [Member]
Restructuring Cost and Reserve [Line Items]
Termination charges	1,800,000
Termination benefits remitted by company	800,000
2014 Plan Year [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	1,000,000
2013 Plan Year [Member]
Restructuring Cost and Reserve [Line Items]
Termination charges		1,700,000
Termination benefits remitted by company		1,100,000
Termination benefits paid for charges recorded in prior periods	600,000
2013 Plan Year [Member] | Salary and Benefits Continuation [Member]
Restructuring Cost and Reserve [Line Items]
Termination benefits remaining to be paid	0
2012 Plan Year [Member]
Restructuring Cost and Reserve [Line Items]
Termination charges			2,900,000
Termination benefits remitted by company			700,000
Termination benefits paid for charges recorded in prior periods		2,200,000
2012 Plan Year [Member] | Salary and Benefits Continuation [Member]
Restructuring Cost and Reserve [Line Items]
Termination benefits remaining to be paid	$ 0	$ 0