Leases - Other information related to finance leases (Details)	6 Months Ended
Jun. 30, 2019
Leases [Abstract]
Remaining lease term (in years)	2 years 8 months 1 day
Discount rate	3.14%

Discount rate used by lessee to determine present value of finance lease payments.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

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