Operating Leases - Balance Sheet Presentation (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Balance Sheet Captions
Right-of-use assets	$ 1,184
Operating lease liabilities	1,264
Other Assets [Member]
Balance Sheet Captions
Right-of-use assets	1,184
Accrued Liabilities [Member]
Balance Sheet Captions
Operating lease liabilities, current	396
Other Long-Term Liabilities [Member]
Balance Sheet Captions
Operating lease liabilities, noncurrent	$ 868