Long-Term Debt Line of Credit (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012 Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2011 Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Oct. 28, 2010 Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2012 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Dec. 31, 2012 Adjusted LIBOR [Member] Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2012 Base Rate Option [Member] Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2012 Maximum [Member] Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2012 Maximum [Member] Convertible Subordinated Debt [Member] Senior Secured Revolving Credit Facility October 2015 [Member]	Dec. 31, 2012 Minimum [Member] Line of Credit [Member] Senior Secured Revolving Credit Facility October 2015 [Member]
Debt Instrument [Line Items]
Redemption, Purchase, or Repurchase Amount	$ 100,000,000
Line of Credit Facility, Maximum Borrowing Capacity				400,000,000
Debt Instrument, Basis Spread on Variable Rate						2.00%	1.00%
Line of Credit Facility, Commitment Fee Percentage		0.35%
Leverage Ratio		2.66	1.81					3.5	3.00
Interest Coverage Ratio		19.00	23.80							3.5
Line of Credit Facility, Remaining Borrowing Capacity		$ 76,841,000
Stated Interest Rate Percentage		9.75%			4.25%