Stockholder's Equity - Quarterly (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	May 19, 2015	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 26, 2018	Dec. 14, 2017
Equity, Class of Stock [Line Items]
Preferred stock dividends declared		$ 1,698	$ 1,698	$ 5,094	$ 5,094
Convertible Preferred Stock, Shares Issued upon Conversion	38.0619
Convertible Preferred Stock, Threshold Percentage of Stock Price Trigger				150.00%
Treasury Stock, Shares [Roll Forward]
Treasury stock, cost, beginning of period				$ 284,300
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions				6,296	22,420
Purchase of treasury stock, cost				43,400
Treasury stock, cost, end of period		334,100		334,100
Dividends, Cash		1,632		4,144
Dividend Paid
Treasury Stock, Shares [Roll Forward]
Dividends, Cash		$ 1,100		$ 3,400
Treasury Stock
Treasury Stock, Shares [Roll Forward]
Treasury stock, shares, beginning of period				18,605,581
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions				505,702
Treasury stock shares received, other				7,026
Purchase of treasury stock, shares				2,974,711
Treasury stock, shares, end of period		22,093,020		22,093,020
Treasury stock, cost, beginning of period				$ 284,301
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions				6,296
Treasury stock received, value, other				96
Purchase of treasury stock, cost				43,442
Treasury stock, cost, end of period		$ 334,135		$ 334,135
Treasury stock, average cost per share, beginning of period, in dollars per share				$ 15.28
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions, Average Cost Per Share				12.45
Treasury stock received, per share, other				13.66
Purchase of treasury stock, average cost per share, in dollars per share				14.60
Treasury stock, average cost per share, end of period, in dollars per share		$ 15.12		$ 15.12
Minimum
Equity, Class of Stock [Line Items]
Convertible Preferred Stock, Threshold Consecutive Trading Days				20 days
Minimum | Call Option
Equity, Class of Stock [Line Items]
Option Indexed to Issuer's Equity, Strike Price				$ 26.27
Maximum
Equity, Class of Stock [Line Items]
Convertible Preferred Stock, Threshold Consecutive Trading Days				30 days
Convertible Preferred Stock
Equity, Class of Stock [Line Items]
Preferred stock issuance, net of issuance costs, shares	120,750
Preferred Stock, Dividend Rate, Percentage	5.625%
Proceeds from Issuance of Preferred Stock, net of issuance costs	$ 117,200
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 3,600
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Convertible Preferred Stock | Retained Earnings/(Accumulated deficit)
Equity, Class of Stock [Line Items]
Preferred stock dividends declared		$ 1,698	$ 1,698	$ 5,094	$ 5,094
Convertible Debt
Treasury Stock, Shares [Roll Forward]
Convertible debt, unamortized discount		$ 11,400		$ 11,400		$ 14,900
2022 convertible note | Convertible Debt
Treasury Stock, Shares [Roll Forward]
Convertible debt, unamortized discount								$ 23,400
Option Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value							$ 29,000