Derivatives and Hedging (Narrative) (Details)	Sep. 30, 2019 shares
Call Option [Member]
Derivative [Line Items]
Aggregate notional amount	305,000
Put Option [Member]
Derivative [Line Items]
Aggregate notional amount	305,000

The number of issuer's shares to which the option contract is indexed.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 5
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

Name:	us-gaap_OptionIndexedToIssuersEquityIndexedShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant