This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	Feb. 02, 2019	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Feb. 06, 2019	Jan. 31, 2017
Subsequent Events [Line Items]
Purchases of non-marketable investments		$ 115,839	$ 0	$ 0
Equity method investments, carrying amount		$ 118,200	$ 2,500
Authorized amount for share repurchases						$ 525,000
Subsequent Event [Member]
Subsequent Events [Line Items]
Purchases of non-marketable investments	$ 34,000
Equity method investments, carrying amount	$ 149,000
Authorized amount for share repurchases					$ 500,000