Commitments and Contingencies (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Long-term Purchase Commitment [Line Items]
Long-term Purchase Commitment, Time Period	12 months
Term of commitments to purchase goods or services related to the operations of properties	one year or less
Range of remaining compliance periods for tax credit syndication arrangements	less than one year to 12 years
Construction Contracts [Member]
Long-term Purchase Commitment [Line Items]
Commitments related to capital spending activities	$ 302.1