XML 70 R55.htm IDEA: XBRL DOCUMENT v3.7.0.1
Significant Accounting Policies (Investment in Marketable Securities)(Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Investment in Marketable Securities          
Marketable securities $ 29,524,000   $ 29,524,000   $ 85,110,000
Cost basis 28,300,000   28,300,000   36,000,000
Proceeds from sale of marketable securities 0 $ 4,300,000 54,400,000 $ 4,300,000  
Marketable securities, realized gain (loss)   $ (100,000) 3,300,000 $ (100,000)  
Fair Value          
Investment in Marketable Securities          
Marketable securities 29,524,000   29,524,000   85,110,000
Equity marketable securities          
Investment in Marketable Securities          
Marketable securities 0   0   48,315,000
Cost basis 0   0   43,300,000
Commercial mortgage-backed securities          
Investment in Marketable Securities          
Marketable securities $ 29,524,000   $ 29,524,000   $ 36,795,000