Accumulated Other Comprehensive Loss (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Unrealized losses on cash flow hedges:
Other Comprehensive Income (Loss), before Tax	$ (4,726)	$ (5,065)
Interest Rate Swap [Member] | Equity in Income of Affiliated Companies [Member]
Unrealized losses on cash flow hedges:
Interest rate swaps entered into by the Company's equity method joint venture investees	$ (4,726)	$ (5,065)