Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Allowances for accounts receivable	$ 24,683	$ 25,388
Allowances for vendor receivables	$ 2,907	$ 1,819
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	223,801,000	220,929,000
Common stock, shares outstanding	223,801,000	220,929,000