Income taxes: (Details 3) (USD $)	12 Months Ended
Dec. 31, 2013
Income taxes
Uncertain tax positions	$ 0
State jurisdictions \| Maximum
Income taxes
Period during which state impact of any federal changes remains subject to examination by various states	1 year

The noncurrent portion of the amount recognized for uncertain tax positions as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LiabilityForUncertainTaxPositionsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant