Long-Term Debt And Notes Payable (Components Of Debt) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Debt Instrument [Line Items]
Net decrease in short-term debt	$ (11,000)	$ 123,197
Long-term debt	749,202		749,170
Short-term borrowings	114,814		125,826
2.75% Notes Due 2018
Debt Instrument [Line Items]
Long-term debt	249,971		249,965
4.45% Notes Due 2023
Debt Instrument [Line Items]
Long-term debt	299,977		299,976
6.55% Notes Due 2036
Debt Instrument [Line Items]
Long-term debt	$ 199,254		$ 199,229