Allowance for Doubtful Accounts (Reserve For Impaired Notes Receivable) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reserve for Impaired Notes Receivable
Balance Beginning of Year	$ 2,019	$ 958	$ 1,066
Additions	2,489	1,072	108
Deductions	1,477	11	216
Balance End of Year	$ 3,031	$ 2,019	$ 958