When deciding a motion to dismiss for failure to state a claim, a court must accept as true all well-pleaded facts and draw all permissible inferences in the plaintiff's favor. There is a strong presumption against dismissal for failure to state a claim under Rule 12(b)(6).
While a complaint "does not need detailed factual allegations, a plaintiff's obligation to provide the 'grounds' of his 'entitlement to relief' requires more than labels and conclusions, and a formulaic recitation of the elements of a cause of action will not do." "Factual allegations must be enough to raise a right to relief above the speculative level, on the assumption that all the allegations in the complaint are true (even if doubtful in fact)."
A claim must be dismissed if the complaint does not contain enough facts to make the claim “plausible on its face.”  A claim is plausible on its face if the complaint contains sufficient facts for a court to draw an inference that the defendant is liable for the alleged misconduct.