CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	Dec. 31, 2018	Dec. 31, 2017	Dec. 06, 2010
3.20% Senior Notes, due June 2023
Stated interest rate	3.20%	3.20%
3.37% Senior Notes, due June 2025
Stated interest rate	3.37%	3.37%
4.50% Senior Notes, due December 2020
Stated interest rate	4.50%	4.50%	4.50%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant