Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 07, 2011
Debt Instrument [Line Items]
Borrowings under short-term line of credit	$ 0	$ 24,219	$ 90,000
Long-term debt
Total current maturities of long-term debt	51,998	15,145
Total long-term debt, less current maturities	375,213	427,243
Nonrecourse
Debt Instrument [Line Items]
Borrowings under short-term line of credit	0	4,219
Long-term debt
Total current maturities of long-term debt	6,012	2,496
Total long-term debt, less current maturities	4,063	20,067
Recourse
Debt Instrument [Line Items]
Borrowings under short-term line of credit	0	20,000
Long-term debt
Total current maturities of long-term debt	45,986	12,649
Total long-term debt, less current maturities	$ 371,150	$ 407,176