Fair Value Measurements - Fair Value of Company's Fixed Rate Senior Notes and Junior Subordinated Debentures (Detail) - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
6.375% Senior Notes [Member] | Estimated Fair Value [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	$ 313,088	$ 304,013
6.375% Senior Notes [Member] | Carrying Amount [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	324,166	323,888
Junior Subordinated Debentures [Member] | Estimated Fair Value [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	143,754	139,831
Junior Subordinated Debentures [Member] | Carrying Amount [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Debt	$ 128,358	$ 128,640