Bootstrapのform-controlクラスに、高さが34pxに固定してしまいました
.form-control {
display: block;
width: 100%;
height: 34px;
padding: 6px 12px;
font-size: 14px;
line-height: 1.42857143;
color: #555;
background-color: #fff;
background-image: none;
border: 1px solid #ccc;
border-radius: 4px;
-webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, .075);
box-shadow: inset 0 1px 1px rgba(0, 0, 0, .075);
-webkit-transition: border-color ease-in-out .15s, -webkit-box-shadow ease-in-out .15s;
-o-transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
}