CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Actuarial gain (loss) on pension plan, tax (benefit)	$ (11,410,000)	$ (1,392,000)	$ 13,092,000
Accumulated Other Comprehensive Loss
Actuarial gain (loss) on pension plan, tax (benefit)	$ (11,410,000)	$ (1,392,000)	$ 13,092,000