Summary of Significant Accounting Policies (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Balance at beginning of period	$ 121	$ 246	$ 431
Charged to expense	3,432	1,728	1,566
Asset disposals	(2,433)	(1,853)	(1,751)
Sale of properties	(581)	0	0
Balance at end of period	$ 539	$ 121	$ 246