Debt Convertible Notes (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended	6 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 26, 2012	Jun. 30, 2012	Dec. 31, 2011	Apr. 25, 2012	Dec. 20, 2011	Dec. 15, 2011
Debt Instrument [Line Items]
Interest Paid	$ 32,278	$ 33,266	$ 34,051
Common Stock, Shares Authorized	60,000,000	60,000,000		60,000,000			30,000,000
Embedded conversion option tax benefit	0	0	8,285
Convertible Notes Due in 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount								57,500	50,000
Convertible Notes Principal Amount								7,500
Convertible debt issued at a percentage of face value, percentage						100.00%
Term of exercise option						30 days
Option to purchase additional principal amount of convertible notes						7,500
Maturity date	Dec. 15, 2017
Stated interest rate on debt	7.00%								7.00%
Interest Paid	4,025	4,025	4,025
Conversion rate, shares per principal amount of convertible notes, shares	97.2384
Conversion rate, principal amount of convertible notes for shares, principal amount	1
Conversion price per share	$ 10.28
Date at which holders may convert their convertible notes at their option	preceding June 15, 2017
Scenarios in Which Holders of Convertible Notes can Convert, Conversion Period Following Measurement Period	5 days
Measurement Period, Consecutive Trading Days.	5 days
Trading price per note for each day of that measurement period	less than 98%
Period of Consecutive Trading Days	30 days
Last reported sale price of the company's common stock	equal to or greater than 130%
Date on which convertible notes will be convertible	Jun. 15, 2017
Option to elect out of conversion If issuance would result in a stated increase in common stock outstanding, stated percentage increase					19.99%
Derivative liability for conversion feature associated with convertible debt								22,330
Effective interest percentage								17.78%
Shareholder approval to convert if issuance would result in a stated increase in common stock outstanding, stated percentage increase				19.99%
Embeded conversion option, value				42,037
Embedded conversion option tax benefit				$ 8,285
Upon fundamental change, percentage of principal amount of convertible notes the company would be required to repurchase	100.00%
Call of convertible notes for redemption	Dec. 20, 2015
Scenarios for call of Convertible Notes, minimum sale price of common stock as a percentage of conversion price	135.00%
Scenarios for call of Convertible Notes, consecutive trading days	30 days
Scenarios for call of Convertible Notes, redemption price	100.00%
Minimum | Convertible Notes Due in 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days	20 days
Scenarios for call of Convertible Notes, period of trading days	20 days