Redeemable Preferred Stock (Details) - USD ($)							12 Months Ended
	Mar. 01, 2019	Nov. 26, 2018	Aug. 29, 2018	May 25, 2018	Jan. 19, 2018	Jun. 22, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Preferred Stock, Shares Issued					350,000			350,000	0
Preferred Stock, Par or Stated Value Per Share					$ 0.01			$ 0.01	$ 0.01
Common Stock, Par or Stated Value Per Share					$ 0.01			$ 0.01	$ 0.01
Issuance of common stock						$ 228,500,000	$ 228,546,000
Payments of Stock Issuance Costs						$ 4,300,000
Preferred Stock, Dividend Rate, Percentage					7.00%
Preferred stock per share annualized dividend					$ 70.00
Preferred Stock, Redemption Price Per Share					$ 33.00
Preferred Stock, Minimum Conversion Amount					$ 50,000,000
Minimum required closing share price for the Company to cause conversion					$ 47.85
Minimum cash consideration in change of control to require conversion					90.00%
Option change in control redemption premium, less than 90% cash transaction					101.00%
Maximum parity stock issuable, amount					$ 250,000,000
Maximum aggregate value of outstanding preferred stock to issue parity stock					$ 100,000,000
Preferred stock ownership required for preemptive rights					75.00%
Preferred stock ownership required to have board observer					50.00%
Minimum ownership required to maintain registration rights					5.00%
Dividends, Preferred Stock, Paid-in-kind		$ 6,300,000	$ 6,200,000	$ 4,800,000
Convertible Preferred Stock, Shares Issued upon Conversion								11,132,121
Cumulative Preferred Stock [Member]
Shares Issued, Price Per Share					$ 1,000
Issuance of common stock					$ 350,000,000
Payments of Stock Issuance Costs					$ 7,700,000
On or prior to the first anniversary of the Issue Date [Domain]
Cash Change of Control Conversion Premium					130.00%
On or prior to the second anniversary of the Issue Date [Domain]
Cash Change of Control Conversion Premium					120.00%
On or prior to the third anniversary of the Issue Date [Domain]
Cash Change of Control Conversion Premium					105.00%
After the third anniversary of the Issue Date [Domain]
Cash Change of Control Conversion Premium					101.00%
Subsequent Event [Member]
Dividends, Preferred Stock, Paid-in-kind	$ 6,400,000