CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Statement Of Stockholders Equity [Abstract]
Cumulative Preferred Stock, par	$ 100	$ 100	$ 100
Cumulative Preferred Stock, authorized	400,000	400,000	400,000
Cumulative Preferred Stock, issued	0	0	0
Common Stock, par	$ 1.00	$ 1.00	$ 1.00
Common Stock, authorized	450,000,000	450,000,000	450,000,000
Common Stock, issued	195,055,724	195,040,149	195,017,103