Condensed Consolidated Statements of Comprehensive Income Loss (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2011	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Tax provision (benefit) for amortization of deferred loss	$ 7	$ 8	$ 21	$ 24
Tax provision (benefit) for amortization of prior service cost	$ 1	$ 1	$ 7	$ 5