Fair Value Measurements Schedule Of Fair Value Of Assets (Details) (USD $)								12 Months Ended																																																		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 250 Million Senior Notes [Member]	Dec. 31, 2011 250 Million Senior Notes [Member]	Dec. 31, 2012 400 Million Senior Notes [Member]	Aug. 25, 2010 Senior Notes 250 Million Senior Notes [Member]	Jun. 27, 2012 Senior Notes 400 Million Senior Notes [Member]	Dec. 31, 2012 Level 1 Mutual Funds	Dec. 31, 2011 Level 1 Mutual Funds	Dec. 31, 2012 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure	Dec. 31, 2011 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure	Dec. 31, 2012 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Cash and Cash Equivalents	Dec. 31, 2011 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Cash and Cash Equivalents	Dec. 31, 2012 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 1	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 1	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 1 Cash and Cash Equivalents	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 1 Cash and Cash Equivalents	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 1 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 1 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 1 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 1 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 2	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 2	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 2 Cash and Cash Equivalents	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 2 Cash and Cash Equivalents	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 2 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 2 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 2 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 2 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 3	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 3	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 3 Cash and Cash Equivalents	Dec. 31, 2011 Fair Value, Measurements, Recurring Level 3 Cash and Cash Equivalents	Dec. 31, 2012 Fair Value, Measurements, Recurring Level 3 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 3 Pension Plans, Defined Benefit Mutual Funds		Dec. 31, 2012 Fair Value, Measurements, Recurring Level 3 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2011 Fair Value, Measurements, Recurring Level 3 Pension Plans, Defined Benefit Money Market Funds		Dec. 31, 2012 Irrevocable trust [Member] Mutual Funds	Dec. 31, 2012 Money Market Funds Level 2 Mutual Funds
Defined Benefit Plan, Fair Value of Assets Sold								$ 11,800,000	$ 0																																																	$ 8,400,000	$ 3,400,000
Debt Instrument, Face Amount						250,000,000	400,000,000
Cash and Cash Equivalents, Fair Value Disclosure												20,001,000	20,001,000											0	0											20,001,000	20,001,000											0	0
Defined Benefit Plan, Fair Value Disclosure	3,486,000	12,094,000												11,884,000	[1]	21,534,000	[1]	4,357,000	[1]	2,238,000	[1]					11,884,000	[1]	21,534,000	[1]	0	[1]	0	[1]					0	[1]	0	[1]	4,357,000	[1]	2,238,000	[1]					0	[1]	0	[1]	0	[1]	0	[1]
Assets, Fair Value Disclosure										36,242,000	43,773,000											11,884,000	21,534,000											24,358,000	22,239,000											0	0
Debt Instruments, Fair Value Disclosure			$ 271,600,000	$ 267,700,000	$ 442,000,000

[1] Included in Investments, employee benefit plans, fair value on consolidated balance sheets.