Retirement Plans (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jan. 01, 2002
Retirement Plans (Additional Textual) [Abstract]
Retirement age for benefit payments, earliest age allowed contingent of minimum service requirement	55
Minimum time period for expected rate of return	10 years
Maximum time period for expected rate of return	20 years
Accrued cost related to retirement plans included in other long term liabilities	$ 45,500,000	$ 26,800,000
Company contribution under deferred compensation plan	200,000	100,000	100,000
Change in equity as a result of change in deferred net loss	12,800,000	1,500,000	(5,600,000)
Change in equity as result of change in deferred net loss taxes	7,200,000	800,000	(3,100,000)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan (Textual) [Abstract]
Retirement age benefit payable to a terminated vested participant upon retirement	65
Number of years of service at the time plan was frozen for the eligibility of benefit payable to terminated vested participant at age 55	15 years
Rate of qualified earnings credited to the account of the participant of benefit plan	3.00%
Accumulated benefit obligation for defined benefit plan	92,575,000	80,278,000	74,882,000
Expected contribution to defined benefit plan	4,500,000
Unrecognized actuarial losses included in other comprehensive loss, net of tax	32,400,000	19,600,000
Unrecognized actuarial losses included in other comprehensive loss	50,600,000	30,600,000
Defined benefit plan amounts that will be amortized from accumulated other comprehensive income loss in next fiscal year	4,700,000
Net loss recognized in other comprehensive income	20,000,000	2,300,000
Pension Plans, Defined Benefit [Member] | Cash [Member]
Defined Benefit Plan (Textual) [Abstract]
Defined benefit plan, cash	4.50%
Pension Plans, Defined Benefit [Member] | Domestic Equity [Member]
Defined Benefit Plan (Textual) [Abstract]
Defined benefit plan, equity securities	42.75%
Pension Plans, Defined Benefit [Member] | International [Member]
Defined Benefit Plan (Textual) [Abstract]
Defined benefit plan, equity securities	11.25%
Pension Plans, Defined Benefit [Member] | Fixed Income Securities [Member]
Defined Benefit Plan (Textual) [Abstract]
Defined Benefit Plan, Debt securities	41.50%
Non Qualified Retirement Plans [Member]
Defined Benefit Plan (Textual) [Abstract]
Accumulated benefit obligation for defined benefit plan	15,200,000
Maximum percentage of Company contribution of employee's salary	4.00%
Retirement Savings Plan [Member]
Defined Benefit Plan (Textual) [Abstract]
Percentage of amount contributed by Company with respect to employee's contribution		100.00%	100.00%
Maximum percentage of Company contribution of employee's salary		4.00%	5.00%
Discretionary profit sharing contribution				2.00%
Company contribution	$ 6,000,000	$ 4,900,000	$ 6,200,000