Retirement Benefits (Details)	3 Months Ended
	Mar. 31, 2019 USD ($)
Retirement Benefits
Expected long-term rate of return on plan assets	1.50%
Service Cost	$ 50,000
Interest Cost	2,000
Expected Return on Plan Assets	(2,000)
Amortization of initial net obligation (asset)	7,000
Amortization of net (gain) loss	2,000
Net periodic benefit cost	59,000
Contributions by employer	172,000
Expected future employer contributions, remainder of 2019	$ 60,000