Operating Lease Rental Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Operating Leases Rent Expense [Abstract]
Minimum rentals	$ 28,110	[1]	$ 24,776	[1]	$ 55,649	[1]	$ 49,044	[1]
Contingent rentals	7,261		7,148		9,684		9,644
Less: Sublease rentals	(243)		(156)		(447)		(310)
Total rent expense	$ 35,128		$ 31,768		$ 64,886		$ 58,378

[1] Minimum rentals include all lease payments as well as fixed and variable common area maintenance (“CAM”), parking and storage fees, which were approximately $2.5 million during the three months ended June 30, 2014 and 2013, respectively, and $4.9 million during the six months ended June 30, 2014 and 2013, respectively.