Stockholders' Equity - Common and Treasury Stock and Series B Convertible Preferred Stock (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2019 shares
Common Shares Issued
Common stock, issued, beginning balance (in shares)	19,067
Common stock, issued, ending balance (in shares)	19,067
Treasury Stock Shares
Treasury stock shares, beginning balance (in shares)	429
Treasury stock shares issued (in shares)	(120)
Treasury stock shares, ending balance (in shares)	309
Common Shares Outstanding
Common stock, outstanding, beginning balance (in shares)	18,638
Common stock, outstanding, ending balance (in shares)	18,758
Common Stock
Common Shares Outstanding
Conversion of outstanding stock (in shares)	120