Equity Preferred Stock (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 15, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares
Class of Stock [Line Items]
Depository shares (in shares) | shares		0	2,000,000
Depository shares interest in preferred stock			0.025
Preferred stock dividend rate		6.95%	6.95%
Preferred stock, par value (in dollars per shares) | $ / shares		$ 1	$ 1
Preferred stock, liquidation preference (in dollars per share) | $ / shares		$ 1,000	$ 1,000
Preferred stock | $		$ 0	$ 47,753
Stock redeemed | $		$ 50,000
Depositary share aggregate liquidation preference | $	$ 50,000
Depositary shares redemption percentage	100.00%
Depositary share redemption price her share (in dollars per share) | $ / shares	$ 25.00
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividend rate			6.95%
Preferred stock, par value (in dollars per shares) | $ / shares			$ 1.00
Preferred stock, liquidation preference (in dollars per share) | $ / shares	$ 1,000.00		$ 1,000
Preferred stock | $			$ 47,800
Stock redeemed | $	$ 50,000
Redemption price percentage	100.00%
Stock redeemed (in shares) | shares	50,000