Borrowings (Details)	3 Months Ended		9 Months Ended		12 Months Ended	9 Months Ended		9 Months Ended		9 Months Ended			9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended				9 Months Ended
	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2014 Note due 2015 [Member] USD ($)	Dec. 31, 2013 Note due 2015 [Member] USD ($)	Sep. 30, 2014 Note due 2018 [Member] USD ($)	Dec. 31, 2013 Note due 2018 [Member] USD ($)	Sep. 30, 2014 Note due 2020 [Member] USD ($)	Dec. 31, 2013 Note due 2020 [Member] USD ($)	Dec. 31, 2013 Note due 2020 [Member] EUR (€)	Sep. 30, 2014 Note due 2021 [Member] USD ($)	Dec. 31, 2013 Note due 2021 [Member] USD ($)	Sep. 30, 2014 Debentures due 2028 [Member] USD ($)	Dec. 31, 2013 Debentures due 2028 [Member] USD ($)	Sep. 30, 2014 Debenture due 2035 [Member] USD ($)	Dec. 31, 2013 Debenture due 2035 [Member] USD ($)	Sep. 30, 2014 Note due 2038 [Member] USD ($)	Dec. 31, 2013 Note due 2038 [Member] USD ($)	Sep. 30, 2014 Note due 2041 [Member] USD ($)	Dec. 31, 2013 Note due 2041 [Member] USD ($)	Sep. 30, 2014 Other long term debt instruments [Member] USD ($)	Dec. 31, 2013 Other long term debt instruments [Member] USD ($)	Sep. 30, 2014 Credit Agreement [Member] USD ($)	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Maximum [Member]
Interest expense and interest income [Abstract]
Interest expense	$ 32,509,000	$ 30,994,000	$ 99,150,000	$ 92,852,000
Interest income	(1,270,000)	(758,000)	(3,279,000)	(2,100,000)
Interest expense, net	31,239,000	30,236,000	95,871,000	90,752,000
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	152,743,000		152,743,000
Short-term borrowings [Abstract]
Current installments	2,566,000		2,566,000		2,778,000
Commercial Paper	150,500,000		150,500,000		226,500,000
Debt, Current	153,066,000		153,066,000		229,278,000
Long-term borrowings [Abstract]
Long-term debt						299,786,000	299,638,000	348,845,000	348,598,000	381,856,000	411,500,000		449,833,000	449,813,000	199,509,000	199,483,000	296,645,000	296,526,000	247,926,000	247,859,000	345,790,000	345,671,000	2,633,000	2,891,000
Carrying amount of long-term debt	2,572,823,000		2,572,823,000		2,601,979,000
Long-term debt (noncurrent)	2,570,257,000		2,570,257,000		2,599,201,000
Debt instruments, maturity date						Oct. 15, 2015		Mar. 15, 2018		Dec. 01, 2020			Mar. 01, 2021		Jun. 01, 2028		Oct. 15, 2035		Mar. 15, 2038		Mar. 01, 2041
Debt instrument, stated interest rate (in hundredths)						4.875%		5.45%		2.125%			4.30%		6.65%		5.375%		6.60%		5.375%
Term of debt instrument (in years)						10 years		10 years		7 years			10 years		30 years		30 years		30 years		30 years
Line of Credit Facility [Abstract]
Line of Credit Facility, Expiration Date																									Nov. 10, 2016	Dec. 31, 2014	Dec. 31, 2020
Unsecured revolving credit facility, maximum borrowing capacity																									1,000,000,000
Line of Credit Facility, Covenant Terms			Under the credit facility, the Company is required to maintain an interest coverage ratio of EBITDA to consolidated net interest expense of not less than 3.0 to 1.
Line of Credit Facility, Covenant Compliance			The Company was in compliance with this covenant and its other long-term debt covenants at September 30, 2014, and it expects to remain in compliance with all of its debt covenants.
Debt Instrument, Face Amount												300,000,000
Proceeds from Issuance of Long-term Debt					$ 403,776,000