Preferred Stock (Details) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
	Jul. 15, 2019 shares	Dec. 31, 2019 USD ($)	Sep. 29, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Apr. 01, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) $ / shares shares	Jul. 26, 2016
Class of Stock [Line Items]
Preferred stock dividends | $		$ 0	$ 971	$ 8,733	$ 8,733	$ 8,733	$ 8,732	$ 8,733	$ 8,733	$ 18,437	$ 34,931	$ 34,931
Depository Shares
Class of Stock [Line Items]
Depository shares issued													5,200,000
Preferred stock ownership interest														0.01
6.75% Series B Mandatory Convertible Preferred Stock
Class of Stock [Line Items]
Percentage of issued shares													6.75%
Offering price (in usd per share) | $ / shares													$ 100
Proceeds from offering, net | $													$ 501,000
Preferred stock converted in to common stock (in shares)	132.50
Number of common stock issued upon conversion (in shares)	6,900,000