Segment Reporting - Assets by Segment (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets
Total Assets	$ 1,266,535	$ 1,175,793
Operating Segments [Member] | United States Excluding All Points [Member]
Assets
Total Assets	928,861	1,133,824
Operating Segments [Member] | All Points [Member]
Assets
Total Assets	8,878	7,298
Operating Segments [Member] | Canada [Member]
Assets
Total Assets	309,215	15,477
Operating Segments [Member] | Mexico [Member]
Assets
Total Assets	17,980	17,816
Operating Segments [Member] | Australia [Member]
Assets
Total Assets	$ 1,601	$ 1,378