Employee Retirement Plans (Schedule Of Contributions Made By The Company To Each Multiemployer Plan) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 333	$ 307	$ 401
National Integrated Group Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	202	186	197
Sheet Metal Workers' National Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	98	50	41
Sheet Metal Workers' Pension Plan Of Northern California [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	33	63	154
Western Metal Industry Pension Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions		$ 8	$ 9