Stock Repurchase Plans (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		37 Months Ended
	Mar. 31, 2020 USD ($) Right item $ / shares	Mar. 31, 2019 USD ($)	Apr. 27, 2020 USD ($) $ / shares shares	Dec. 31, 2019 $ / shares	Mar. 30, 2017 USD ($)
Equity, Class of Treasury Stock
Value of shares repurchased | $	$ 6	$ 4
Par value | $ / shares	$ 1.00			$ 1.00
Preferred share purchase right
Equity, Class of Treasury Stock
Dividend, Preferred share purchase right | Right	1
Share price | $ / shares	$ 75.00
Exercisable exercise price of the Right | item	2
Series B Junior Preferred Stock | Preferred share purchase right
Equity, Class of Treasury Stock
Percentage of purchase of a preferred shares represented by rights	0.001
Par value | $ / shares	$ 1.00
March 2017 Stock Repurchase Plan
Equity, Class of Treasury Stock
Amount authorized of shares to be repurchased under Stock Repurchase Program | $					$ 500,000
Total number of shares purchased (in shares) | shares			4,605
Value of shares repurchased | $			$ 268,300
Shares acquired, average cost (in dollars per share) | $ / shares			$ 58.26
Permitted dollar value of repurchases remaining | $			$ 231,700