Lease Agreements (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leased Assets [Line Items]
Base rent	$ 32,600,000	$ 31,200,000	$ 30,900,000
Contingent rental expense	1,700,000	1,600,000	1,100,000
Total minimum lease payments	209,888,000
Monthly equipment lease payment	218,000
Equipment lease payments term	60 months
Australia [Member]
Operating Leased Assets [Line Items]
Number of properties leased	13
Number of properties	18
New Zealand [Member]
Operating Leased Assets [Line Items]
Number of properties leased	4
Number of properties	8
United States [Member]
Operating Leased Assets [Line Items]
Number of properties not leased	1
Australia And New Zealand [Member]
Operating Leased Assets [Line Items]
Total minimum lease payments	90,200,000
Minimum [Member]
Operating Leased Assets [Line Items]
Lease term	1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Lease term	38 years
Equipment Lease [Member]
Operating Leased Assets [Line Items]
Lease term	5 years
Total minimum lease payments	$ 13,465,000