Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Property, plant and equipment
Land	$ 1,764	$ 2,152
Building improvements	596,655	581,286
Machinery and equipment	390,069	360,199
Capitalized leases for machinery, equipment and buildings	22,444	35,129
Property, plant and equipment, gross	1,010,932	978,766
Accumulated depreciation and amortization	(373,931)	(313,067)
Property Plant and Equipment Net before Construction in Progress	637,001	665,699
Construction in Progress	12,590	18,303
Property, plant and equipment, net	$ 649,591	$ 684,002