Income Taxes Income Taxes - Valuation allowance for deferred tax assets (Details) (Deferred Income Tax Asset Valuation Allowance, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Deferred Income Tax Asset Valuation Allowance
Valuation allowance for deferred tax assets [Roll Forward]
Balance at beginning of the year	$ 1,213	$ 1,334	$ 1,487
Charged to Expenses	158	168
Charged to other accounts	(83)	0
Deductions	(14)	(289)
Balance at end of the year	$ 1,274	$ 1,213	$ 1,487