Preferred Stocks (Details) - USD ($)	Apr. 01, 2017	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Payments for repurchase of redeemable preferred stock	$ 15,600,000
Redeemable preferred stock classified as long term debt	$ 300,000
Preferred stock
Class of Stock [Line Items]
Preferred stock, shares authorized		2,000,000.0
Preferred stock, par value per share		$ 100
Preferred stock, shares oustanding		0	0
Preferred stock, series 4.50%
Class of Stock [Line Items]
Preferred stock, dividend rate, percentage	4.50%
Preferred stock, redemption price per share	$ 105
Preferred stock, series 4.70%
Class of Stock [Line Items]
Preferred stock, dividend rate, percentage	4.70%
Preferred stock, redemption price per share	$ 102