Consolidated Statements of Operations (Parentheticals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Preferred stock dividends, accretion of issuance cost	$ 0	$ 0	$ 1,081

Amount of decrease to net income for accretion of temporary equity to its redemption value to derive net income apportioned to common stockholders.

No definition available.

Name:	us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration