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Schedule of Estimated Fair Value (Detail) - USD ($)
$ in Thousands
Jun. 18, 2017
Jan. 01, 2017
2012 Seven Year Fixed Rate Notes [Member]    
Debt Instrument [Line Items]    
Principal Amount $ 910,252 $ 916,650
Fair Value 918,444 932,233
2015 Class Five-Year Notes [Member]    
Debt Instrument [Line Items]    
Principal Amount 493,750 495,000
Fair Value 493,256 485,595
2015 Ten-Year Notes [Member]    
Debt Instrument [Line Items]    
Principal Amount 790,000 792,000
Fair Value $ 797,110 $ 765,864