Convertible Notes, Long-Term Debt and Credit Facility Convertible Notes, Long-Term Debt and Credit Facility (Convertible Notes) (Details) (USD $)	0 Months Ended	12 Months Ended				0 Months Ended			1 Months Ended	9 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended
	Feb. 14, 2008	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2010	Dec. 31, 2012 2008 Notes [Member]	Jun. 25, 2012 2008 Notes [Member]	Feb. 14, 2008 2008 Notes [Member]	May 31, 2011 2008 Notes [Member]	Sep. 30, 2013 2008 Notes [Member]	Dec. 31, 2013 2008 Notes [Member]	Feb. 15, 2013 2008 Notes [Member]	Mar. 31, 2010 2008 Notes [Member]	Jan. 05, 2012 2010 Notes [Member]	Dec. 31, 2013 2010 Notes [Member]	Mar. 31, 2010 2010 Notes [Member]	Mar. 31, 2010 Exchange Agreement [Member]
Debt Instrument [Line Items]
Notes repurchased						$ 50,300,000	$ 15,000,000					$ 5,200,000		$ 36,000,000
Percentage of original principal amount of notes plus accrued and unpaid interest equalized repurchase							102.00%							104.95%
Notes Issued								115,000,000
Convertible notes, interest rate								5.25%
Maturity date								Feb. 15, 2028							Feb. 15, 2028
Debt Instrument, Interest Rate, Effective Percentage										11.50%
Expected Term for Accretion of Debt Discount										5 years
Debt Instrument, Call Date, Latest											Feb. 15, 2013
Federal statutory tax rate	38.00%	35.00%	35.00%	35.00%
Discount on notes								27,800,000
Deferred tax liability on notes								10,600,000
Convertible notes for each $1,000 principal amount, amount of notes exchanged													40,000,000
Convertible notes for each $1,000 principal amount, amount of aggregate consideration																36,000,000
Senior credit facility, value of common stock converted																	2,000,000
Debt Discount Accreted Percentage					9.90%
Redeemable price as a percentage of outstanding principal note amount											100.00%
Common stock issued in payment of debt, shares		43.9560
Convertible notes for each $1000 principal amount, principal amount of 2010 Notes converted		1,000
Debt Instrument, Convertible, Conversion Price		$ 22.75
Amount of notes exchanged									4,500,000
Convertible notes for each $1,000 principal amount, number of shares									559,007
Loss on the extinguishment of debt						900,000	1,000,000		1,100,000					5,400,000
Cash premium loss recognized on conversion of debt		$ (55,000)	$ (3,710,000)	$ (5,295,000)		$ 300,000	$ 300,000							$ 1,800,000