Shareholders’ Equity and Earnings Per Share - Series C Preferred Stock (Details) - $ / shares	Sep. 12, 2016	Jun. 21, 2010	Dec. 31, 2017	Dec. 31, 2016
Series C Preferred Stock
Preferred stock, par value (in dollars per share)			$ 0	$ 0
Par value of common stock (in dollars per share)			$ 0	$ 0
Series C Preferred Stock
Series C Preferred Stock
Number of convertible preferred shares converted (in shares)		21,004
Number of common stock into which preferred stock are convertible (in shares)		5,601,000
Conversion price (in dollars per share)		$ 3.75
Preferred Stock, Liquidation Preference Per Share		$ 1,000
Preferred Stockholders
Series C Preferred Stock
Common shares issued in exchange of convertible perpetual preferred stock (in shares)	5,601,000
Par value of common stock (in dollars per share)	$ 0
Preferred Stockholders | Series C Preferred Stock
Series C Preferred Stock
Number of convertible preferred shares converted (in shares)	21,004
Preferred stock, par value (in dollars per share)	$ 0