Employee Benefit Plans - Summary of Weighted-Average Asset Allocations by Asset Category (Detail)	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Assets Target Allocations [Line Items]
Total	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Total	65.00%	62.00%
Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	55.00%
Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	75.00%
Debt Securities [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Total	31.00%	35.00%
Debt Securities [Member] | Minimum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	25.00%
Debt Securities [Member] | Maximum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	55.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Total	4.00%	3.00%
Cash and Cash Equivalents [Member] | Minimum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	0.00%
Cash and Cash Equivalents [Member] | Maximum [Member]
Defined Benefit Plan Assets Target Allocations [Line Items]
Target Allocation	5.00%