CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY [parenthetical] (USD $)	9 Months Ended
Sep. 30, 2013
Stock Issued During Period Average Sales Price Market Equity Offering Program	$ 3.06

Average sales price of stock issued during the period under at-the-market equity offering program.

No definition available.

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Namespace Prefix:	chtp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration