The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The price per share of the conversion feature embedded in the debt instrument.

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Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Price of a single share of a number of saleable stocks of a company.

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Convertible Notes, Net - Summary of Outstanding Convertible Senior Notes (Parenthetical) (Detail)		12 Months Ended
	Jun. 28, 2017 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 29, 2017 $ / shares
5.25% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price			$ 32.18
Convertible Notes, debt conversion, common stock issued, in percent		36.1380
5.25% Convertible Senior Notes [Member] \| Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount \| $		$ 1,000
4.38% Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, common stock issued, in percent		28.0324
4.38% Convertible Senior Notes [Member] \| Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount \| $		$ 1,000
Convertible Senior Notes [Member] \| Class A Common Stock [Member]
Debt Instrument [Line Items]
Convertible Notes, debt conversion, principal amount \| $	$ 1,000
Debt instrument, conversion price	$ 27.99
Convertible Notes, debt conversion, common stock issued, in percent	35.7236
5.25% Convertible Senior Notes Issued in November 2013 [Member] \| Class A Common Stock [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price		$ 27.67
4.38% Convertible Senior Notes Issued in May 2017 [Member] \| Class A Common Stock [Member]
Debt Instrument [Line Items]
Debt instrument, conversion price		$ 35.67