Schedule II - Valuation And Qualifying Accounts (Details) (Valuation reserve for deferred tax asset, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Valuation reserve for deferred tax asset
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 18,214	$ 15,133	$ 0
Other Additions	2,458	3,081	15,133
Deductions	0	0	0
Balance at end of year	$ 20,672	$ 18,214	$ 15,133