Notes Payable, Collateralized and Short-Term Borrowings (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings	$ 446,532	$ 345,516
8.75% Convertible Notes [Member]
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings	150,000	150,000
4.50% Convertible Notes [Member]
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings	142,247	138,976
8.125% Senior Notes [Member]
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings	108,755
Collateralized borrowings [Member]
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings	45,530	42,940
Short-term borrowings [Member]
Notes payable, collateralized and short-term borrowings
Notes payable, collateralized and short-term borrowings		$ 13,600