Significant Accounting Policies (Recently Adopted Accounting Standards) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Accounting Policies [Abstract]
Reclassification from AOCI to retained earnings	$ 435,000
Equity securities, unrealized loss	(162,000)
Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment - gains on equity securities	$ 2,107,000