Annual report pursuant to Section 13 and 15(d)

Leases (Narrative)(Details)

v3.8.0.1
Leases (Narrative)(Details)
12 Months Ended
Dec. 31, 2017
Minimum [Member]  
Operating Leased Assets [Line Items]  
Initial lease term 10 years
Lease terms renewal 10 years
Maximum [Member]  
Operating Leased Assets [Line Items]  
Initial lease term 15 years
Lease terms renewal 15 years