Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2018	Dec. 31, 2017
Consolidated Balance Sheets
Preferred stock-par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock-shares authorized	5,000	5,000
Preferred stock-shares issued	0	0
Class A Common stock-par value (in dollars per share)	$ 0.01	$ 0.01
Class A Common stock-shares authorized	250,000	250,000
Class A Common stock-shares issued	99,701	99,701
Class A Common stock-shares outstanding	76,790	82,687
Common shares in treasury	22,911	17,014