Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par or stated value per share (in dollars per share)	$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par or stated value per share (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares, issued (in shares)	49,014,925	38,734,873
Treasury stock, shares (in shares)	1,514,984	1,474,861