Employee Benefit Plans (Narrative) (Details) - USD ($)	1 Months Ended			3 Months Ended		12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discretionary contribution as percentage of employee's base pay						15.00%
Employer discretionary contribution		$ 112,708	$ 63,500
Vesting period of employer discretionary contribution		2 years	2 years
Defined Contribution Plan, Cost Recognized		$ 56,354				$ 1,100,000	$ 1,000,000
Lump sum paid in lieu of pension benefits					$ 1,700,000
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution	$ 119,252
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation					38,200,000	$ 41,800,000	38,200,000
Average return on pension portfolio assets						7.42%
Expected long-term return on pension portfolio assets						7.00%
Defined Benefit Plan, Contributions by Employer				$ 3,000,000		$ 3,000,000	3,000,000
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized			$ 31,770
Defined Benefit Plan, Accumulated Benefit Obligation					$ 6,300,000	7,600,000	6,300,000
Defined Benefit Plan, Contributions by Employer						$ 207,000	$ 141,000