Pension and Other Post Retirement Benefit Plans - Retirement and Income Savings Plan (Details) (USD $)	12 Months Ended				36 Months Ended	60 Months Ended	36 Months Ended	60 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Dec. 31, 2012 Minimum	Dec. 31, 2009 Minimum	Dec. 31, 2012 Maximum	Dec. 31, 2009 Maximum
Schedule of Defined Contribution Plans Disclosures [Line Items]
Liability recorded due to defined benefit plan withdrawal				$ 6,000,000
Amount of discretionary contributions made by employer to defined contribution plan, percent	50.00%
Maximum Annual Contribution Per Employee, Percent	6.00%
Requisite Service Period	1000 hours
Employer Matching Contribution, Percent of Employees' Gross Pay	2.00%				2.00%	2.00%	7.00%	7.00%
Vesting Period	5 years
Expense Recognized In The Period	$ 3,138,000	$ 2,914,000	$ 2,824,000