Lease Obligations (Additional Lease Information) (Narrative) (Details)	Mar. 31, 2019
Leases [Abstract]
Finance leases, weighted average remaining lease term (in years)	2 years 9 months 18 days
Finance leases, weighted average discount rate, percent	4.30%
Operating leases, weighted average remaining lease term (in years)	4 years 6 months
Operating leases, weighted average discount rate, percent	4.40%