It is not idiomatic. क्या has two uses and it is 'what' in only one of them. When used as 'what', क्या should always be placed before a verb.
This is an example of the second usage where क्या is used to convert a statement into a yes/no question. Any statement can be converted to a yes/no question by placing a क्या at the beginning. For example, मैं नब्बे साल का हूँ। (I am ninety years old) becomes क्या मैं नब्बे साल का हूँ? (Am I ninety years old?), तुम रोज़ पढ़ते हो। (You study every day) becomes क्या तुम रोज़ पढ़ते हो? (Do you study every day?)