Pension and Postretirement Plans (Fair Value of Pension Plan Assets) (Details 10) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Level 1 [Member] | Cash equivalents and other short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	$ 196,757	$ 195,389
Level 1 [Member] | U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	1,383,738	1,315,378
Level 1 [Member] | International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	699,649	482,431
Level 1 [Member] | Corporate debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 1 [Member] | Other fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value		2,501
Level 1 [Member] | Total investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	2,280,144	1,995,699
Level 2 [Member] | Cash equivalents and other short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	84,706	62,922
Level 2 [Member] | U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] | International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	0	0
Level 2 [Member] | Corporate debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	5,147	6,054
Level 2 [Member] | Other fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value		313
Level 2 [Member] | Total investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	89,853	69,289
Estimate of Fair Value Measurement [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	2,371,849	2,071,145
Estimate of Fair Value Measurement [Member] | Cash equivalents and other short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	281,463	258,311
Estimate of Fair Value Measurement [Member] | U.S. equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	1,383,738	1,315,378
Estimate of Fair Value Measurement [Member] | International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	699,649	482,431
Estimate of Fair Value Measurement [Member] | Corporate debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	5,147	6,054
Estimate of Fair Value Measurement [Member] | Other fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value		2,814
Estimate of Fair Value Measurement [Member] | Total investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	2,369,997	2,064,988
Estimate of Fair Value Measurement [Member] | Receivables [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets at fair value	$ 1,852	$ 6,157