Condensed Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Inventory net allowance	$ 76,194htgm_AllowanceOnInventory	$ 54,269htgm_AllowanceOnInventory
Preferred stock, shares authorized	472,083,383us-gaap_TemporaryEquitySharesAuthorized
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	600,000,000us-gaap_CommonStockSharesAuthorized	600,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	335,152us-gaap_CommonStockSharesIssued	334,003us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	333,756us-gaap_CommonStockSharesOutstanding	332,607us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	1,396us-gaap_TreasuryStockShares	1,396us-gaap_TreasuryStockShares
Series A Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	1,406,369	1,406,369
Preferred stock, shares authorized	1,292,084	1,292,084
Preferred stock, shares issued	1,292,084	1,292,084
Preferred stock, shares outstanding	1,292,084	1,292,084
Series B Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	2,104,811	2,104,811
Preferred stock, shares authorized	11,919,624	11,919,624
Preferred stock, shares issued	6,789,712	6,789,712
Preferred stock, shares outstanding	6,789,712	6,789,712
Series C-1 Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	4,581,944	4,581,944
Preferred stock, shares authorized	17,530,800	17,530,800
Preferred stock, shares issued	13,242,612	13,242,612
Preferred stock, shares outstanding	13,242,612	13,242,612
Series C-2 Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	2,244,343	2,244,343
Preferred stock, shares authorized	19,262,522	19,262,522
Preferred stock, shares issued	9,948,331	9,948,331
Preferred stock, shares outstanding	9,948,331	9,948,331
Series D Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	68,604,412	68,604,412
Preferred stock, shares authorized	237,031,908	237,031,908
Preferred stock, shares issued	139,529,173	139,529,173
Preferred stock, shares outstanding	139,529,173	139,529,173
Series E Redeemable Convertible Preferred Stock
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, liquidation value	$ 21,081,517	$ 21,081,517
Preferred stock, shares authorized	185,046,445	185,046,445
Preferred stock, shares issued	45,989,722	45,989,722
Preferred stock, shares outstanding	45,989,722	45,989,722

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