Fair Value Measurements - Fair Value of Company's Fixed Rate Senior Notes and Junior Subordinated Debentures (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
6.375% Senior Notes [Member] | Estimated Fair Value [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	$ 318,450	$ 325,050
6.375% Senior Notes [Member] | Carrying Amount [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	325,277	325,000
Junior Subordinated Debentures [Member] | Estimated Fair Value [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	134,222	148,098
Junior Subordinated Debentures [Member] | Carrying Amount [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	$ 127,167	$ 124,475