Long-Term Debt And Notes Payable (Components Of Debt) (Parenthetical) (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Dec. 31, 2013
2.75% Notes Due 2013
Debt Instrument [Line Items]
Debt instrument interest rate		2.75%	2.75%
Debt instrument maturity year	2018	2018
4.45% Notes Due 2018
Debt Instrument [Line Items]
Debt instrument interest rate		4.45%	4.45%	2.75%
Debt instrument maturity year	2023	2023
6.55% Notes Due 2036
Debt Instrument [Line Items]
Debt instrument interest rate		6.55%	6.55%
Debt instrument maturity year	2036	2036