CONDENSED CONSOLIDATED BALANCE SHEETS [Parenthetical] - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Redeemable preferred stock, par value (in dollars per share)	$ 0.60	$ 0.60
Redeemable preferred stock, authorized	200,000	200,000
Redeemable preferred stock, issued	41,033	33,488
Redeemable preferred stock, outstanding	41,033	33,488
Class A common stock [Member]
Common stock, par value (in dollars per share)	$ 0.60	$ 0.60
Common stock, authorized	24,655,000	24,655,000
Common stock, issued	14,959,309	14,918,869
Common stock, outstanding	14,959,309	14,918,869
Class B common stock [Member]
Common stock, par value (in dollars per share)	$ 0.60	$ 0.60
Common stock, authorized	145,000	145,000
Common stock, issued	0	0