Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Preferred Stock Series D, E, F, G and I, liquidation preference per share (in dollars per share)	$ 25.00	$ 25.00
Common Stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	200,000	200,000
Common Stock, shares issued (in shares)	142,527	140,028
Common Stock, shares outstanding (in shares)	83,610	81,920
Treasury stock, par value (in dollars per share)	$ 0.001	$ 0.001
Treasury stock, shares (in shares)	58,917	58,108