Schedule II - Valuation and Qualifying Accounts (Details) (Allowance for Doubtful Accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2010
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 399		$ 472				$ 161
Additions to Bad Debt Expense or Deferred Tax Asset	0		204		325
Charged to Other Accounts	0		0		0
Deductions	(214)	[1]	(277)	[1]	(14)	[1]
Balance at End of Period	$ 185		$ 399		$ 472		$ 161

[1] Deductions represent the actual write-off of accounts receivable balances.