Stockholders Equity - Annual (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	May 19, 2015 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) class $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($)	Jun. 26, 2018 USD ($)
Equity, Class of Stock [Line Items]
Embedded Cash Conversion Option		$ (596)	$ 28,974
Common stock, shares authorized | shares		125,000,000
Preferred stock dividends declared		$ 6,792	6,792	$ 6,792
Convertible Preferred Stock, Shares Issued upon Conversion | shares	38.0619
Convertible Preferred Stock, Threshold Percentage of Stock Price Trigger		150.00%
Treasury Stock, Cost [Roll Forward]
Treasury stock, cost, beginning of period		$ 234,100
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions		15,217	12,310	11,889
Purchase of treasury stock, cost		34,500
Treasury stock, cost, end of period		$ 284,300	$ 234,100
Treasury Stock, Average Cost Per Share [Roll Forward]
Preferred stock, shares authorized | shares		10,000,000	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Number of classes | class		2
Treasury Stock
Treasury Stock, Shares [Roll Forward]
Treasury stock, shares, beginning of period | shares		15,336,871
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions | shares		1,005,387
Treasury stock shares received, other | shares		29,687
Purchase of treasury stock, shares | shares		2,233,636
Treasury stock, shares, end of period | shares		18,605,581	15,336,871
Treasury Stock, Cost [Roll Forward]
Treasury stock, cost, beginning of period		$ 234,142
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions		15,217
Treasury stock received, value, other		457
Purchase of treasury stock, cost		34,485
Treasury stock, cost, end of period		$ 284,301	$ 234,142
Treasury Stock, Average Cost Per Share [Roll Forward]
Treasury stock, average cost per share, beginning of period, in dollars per share | $ / shares		$ 15.27
Shares purchased for minimum tax withholding under the Equity Plan or other similar transactions, Average Cost Per Share | $ / shares		15.14
Treasury stock received, per share, other | $ / shares		15.39
Purchase of treasury stock, average cost per share, in dollars per share | $ / shares		15.44
Treasury stock, average cost per share, end of period, in dollars per share | $ / shares		$ 15.28	$ 15.27
Convertible Preferred Stock
Equity, Class of Stock [Line Items]
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 | $ / shares	$ 1,000
Treasury Stock, Average Cost Per Share [Roll Forward]
Stock Issued During Period, Shares, Other | shares	120,750
Convertible Preferred Stock | Retained Earnings/(Accumulated deficit)
Equity, Class of Stock [Line Items]
Preferred stock dividends declared		$ 6,792	$ 6,792	$ 6,792
Common Stock Class A
Equity, Class of Stock [Line Items]
Common stock, shares authorized | shares		62,500,000	62,500,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Treasury Stock, Shares [Roll Forward]
Treasury stock, shares, beginning of period | shares		15,336,871
Treasury stock, shares, end of period | shares		18,605,581	15,336,871
Treasury Stock, Cost [Roll Forward]
Treasury stock, cost, beginning of period		$ 234,142
Treasury stock, cost, end of period		$ 284,301	$ 234,142
Common Stock Class B
Equity, Class of Stock [Line Items]
Common stock, shares authorized | shares		62,500,000	62,500,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Call Option
Equity, Class of Stock [Line Items]
Option indexed to Issuer's Equity, Value	$ 15,900
Maximum
Equity, Class of Stock [Line Items]
Convertible Preferred Stock, Threshold Consecutive Trading Days		30 days
Maximum | Call Option
Equity, Class of Stock [Line Items]
Option Indexed to Issuer's Equity, Strike Price | $ / shares		$ 33.54
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 | $ / shares		$ 26.27
Convertible Debt | 2022 convertible note
Treasury Stock, Cost [Roll Forward]
Purchase of treasury stock, cost		$ 19,500
Treasury Stock, Average Cost Per Share [Roll Forward]
Option Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value					$ 29,000