DRV2511Q1EVM: DC input bias network required to establish the input common mode operating voltage

Hi

I'm wanting to know whether the DRV2511Q1 requires a common mode bias voltage be established at IN+ and IN-.

I've got a circuit someone else designed where they have AC coupled a differential signals to IN+ and IN- of the DRV2511Q1,  without any bias network to establish the DC operating point.

I see the gain resistors set what I assume is the differential mode input resistance.  Does this also set the DC input impedance to ground, or are these high impedance nodes?