Debt (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Debt Payments (excluding bank line of credit)
2012, Total	$ 335,050
2012, Principal	134,762
2012, Interest	200,288
2013, Total	337,546
2013, Principal	150,610
2013, Interest	186,936
2014, Total	186,956
2014, Principal	177
2014, Interest	186,779
2015, Total	336,913
2015, Principal	150,145
2015, Interest	186,768
2016 ,Total	671,707
2016, Principal	500,134
2016, Interest	$ 171,573

Name:	us-gaap_LongTermDebtByMaturityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of long-term debt maturing within the next twelve months following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates.