Debt - Schedule of Senior Unsecured Note Issued (Parenthetical) (Detail) - Jun. 30, 2015	Total
Floating Rate Notes due June 15, 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jun. 15, 2016
1.800% Notes due December 15, 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	1.80%
Debt Instrument, Maturity Date	Dec. 15, 2017
2.675% Notes due December 15, 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	2.675%
Debt Instrument, Maturity Date	Dec. 15, 2019
3.734% Notes due December 15, 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	3.734%
Debt Instrument, Maturity Date	Dec. 15, 2024
4.685% Notes due December 15, 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	4.685%
Debt Instrument, Maturity Date	Dec. 15, 2044
1.450% Senior Notes due May 15, 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	1.45%
Debt Instrument, Maturity Date	May 15, 2017
6.375% Senior Notes due August 1, 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	6.375%
Debt Instrument, Maturity Date	Aug. 01, 2019
3.300% Senior Notes due March 1, 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	3.30%
Debt Instrument, Maturity Date	Mar. 01, 2023
3.875% Senior Notes due May 15, 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	3.875%
Debt Instrument, Maturity Date	May 15, 2024
4.875% Senior Notes due May 15, 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate	4.875%
Debt Instrument, Maturity Date	May 15, 2044