One solution is to use the \bracr macro as below:

or as Stephan Lehmke suggested, use display math:

References:
CodeL
\documentclass[12pt,letterpaper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{makeidx}
\usepackage{graphicx}
\usepackage{lmodern}
\usepackage{kpfonts}
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm,showframe]{geometry}
\makeatletter
\def@BracContents{} % default (used by \suchthat)
\newcommand{\BracKern}{\kern-\nulldelimiterspace}
\newcommand{@Brac}[3]{% #1,#3 = left/right bracket type
\ensuremath{%
\begingroup\def@BracContents{#2}%
\mathopen{\left#1\vphantom{#2}\BracKern\right.}% left bracket
#2% content
\mathclose{\left.\BracKern\vphantom{#2}\right#3}% right bracket
\endgroup%
}%
}
\newcommand{\bracr}[1]{@Brac{(}{#1}{)}}%
\makeatother
\begin{document}
\section{Use macro:}
where the first equality in \ref{inequality} follows from $\lceil\frac{s}%
{t}\rceil=\lfloor\frac{s+t-1}{t}\rfloor$ for integer $s$ and $t$ and the
inequality follows from the feasibility condition. We also assume that the
item can be ordered at any day of the week and these orders arrive instantly.
For each day $t\in W$ define $p_{x,t,n,j} \bracr{
\text{for all }x=0,\cdots,u_{j}\text{ }\text{and }
n\in N_{x,t,j}
}$ to be the joint probability of
\section{Display Math:}
where the first equality in \ref{inequality} follows from $\lceil\frac{s}%
{t}\rceil=\lfloor\frac{s+t-1}{t}\rfloor$ for integer $s$ and $t$ and the
inequality follows from the feasibility condition. We also assume that the
item can be ordered at any day of the week and these orders arrive instantly.
For each day $t\in W$ define
[
p_{x,t,n,j} \left(
\text{for all }x=0,\cdots,u_{j}\text{ }\text{and }
n\in N_{x,t,j}
\right)
]
to be the joint probability of
\end{document}
\left...\rightcan't be broken, so you're giving the paragraph formatter an impossible problem to solve. Either (a) use a displayed formula or (b) leave out\leftand\rightor (c) use\raggedright. – Stephan Lehmke Nov 20 '12 at 06:13$p_{x,t,n,j}$ for all $x=0,\cdots,u_{j}$ and $n\in N_{x,t,j}$, (e) combining (dd) and text braces. (Note, that your\left(hasn't a space preceding it.) – Qrrbrbirlbel Nov 20 '12 at 06:30