Pension And Postretirement Benefits (Summary Of Pension Plan Assets Valued Using Net Asset Value (NAV) Or Its Equivalent) (Details) (Pension Benefits [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Archstone Offshore Fund, Ltd [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 30,605	[1],[2]	$ 28,241	[1],[2]
Redemption Frequency	12 Months	[1]	12 Months	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	90 days written	[1]	90 days written	[1]
Evanston Capital Management [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	25,587	[1],[2]	24,055	[1],[2]
Redemption Frequency	12 Months	[1]	12 Months	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	65 days written	[1]	65 days written	[1]
Strategic Value Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	17,238	[1],[2]	15,671	[1],[2]
Redemption Frequency	12 Months	[1]	12 Months	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	90 days written	[1]	90 days written	[1]
U.S. Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	80,171	[1],[2]	26,322	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
Non-U.S. Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	178,841	[1],[2]	198,655	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
Non-U.S. Fixed Income, Government And Corporate [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	181,073	[1],[2]	159,611	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
International Property Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	9,445	[1],[2]	9,011	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
International Balanced Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	8,836	[1],[2]	8,223	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
U.S. Government and Corporate Fixed Income [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	43,182	[1],[2]	33,810	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]
U.S. Tactical Allocation Balanced Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 18,997	[1],[2]	$ 16,455	[1],[2]
Redemption Frequency	immediate	[1]	immediate	[1]
Unfunded Commitment	None	[1]	None	[1]
Other Redemption Restrictions	None	[1]	None	[1]
Redemption Notice Period	None	[1]	None	[1]

[1]

[2] The fair values of the investments have been estimated using the net asset value of the investment