Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred Stock, shares authorized	100,000,000	100,000,000
Preferred Stock, shares issued	5,200,000	5,200,000
Preferred stock, shares outstanding	5,200,000	5,200,000
Common stock, par value (per share)	$ 1.00	$ 1.00
Common stock, shares authorized	342,857,143	342,857,143
Common stock, shares issued	141,007,636	140,592,409
Common stock, shares outstanding	124,047,659	129,547,032
Treasury stock, shares at cost	16,959,977	11,045,377