Commitments and Contingencies - Schedule of Unions Representing Employees and the Expiration Date for Agreements (Detail)	12 Months Ended
	Dec. 31, 2016
Lima Ohio [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 908
Expiration Dates	2019-01
Bellefontaine Ohio GTL Truck Lines Inc [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 908
Expiration Dates	2019-02
Bellefontaine Ohio General Merchandise Service Division [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 908
Expiration Dates	2019-02
Grand Rapids Michigan [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 406
Expiration Dates	2017-10
Landover Maryland [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 639
Expiration Dates	2018-02
Norfolk Virginia [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 822
Expiration Dates	2019-04
Columbus Georgia [Member]
Commitments And Contingencies [Line Items]
Union Locals	IBT 528
Expiration Dates	2019-09