Business and summary of significant accounting policies - Concentrations of credit risk (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Concentration Risk [Line Items] | ||
| Cash balances in excess of federally insured limits | $ 897,383 | $ 6,484,314 |
| Allowance for uncollectible accounts receivable | $ 0 | $ 0 |
| Total Revenue [Member] | Geographic Concentration Risk [Member] | New York Downtown [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 10.00% | |
| Total Revenue [Member] | Geographic Concentration Risk [Member] | New York Midtown [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 9.00% | |
| Total Revenue [Member] | Geographic Concentration Risk [Member] | Las Vegas [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 17.00% | |
| Total Revenue [Member] | Geographic Concentration Risk [Member] | London [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, percentage | 15.00% |
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- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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