Contingencies - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
	Jul. 25, 2014	Dec. 31, 2016
Minimum [Member]
Aggregate range of reasonably possible losses on legal matters in excess of the accrued liability		$ 0
Maximum [Member]
Aggregate range of reasonably possible losses on legal matters in excess of the accrued liability		190
Cash payment for litigation [Member] | Potential Mortgage Servicing Settlement and Claims [Member]
Loss Contingency, Damages Awarded, Value		50
Civil money penalty [Member] | Consent Order Foreclosure Actions [Member]
Loss Contingency, Damages Awarded, Value	$ 160
Consumer relief obligation [Member] | Potential Mortgage Servicing Settlement and Claims [Member]
Loss Contingency, Damages Awarded, Value		$ 500