Leasing Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Future minimum capital lease payments
2015	$ 1,732,000
2016	1,732,000
2017	1,732,000
2018	2,022,000
2019	1,521,000
Subsequent to 2019	3,997,000
Total minimum lease payments	12,736,000
Amounts representing interest	1,098,000
Present value of net minimum lease payments	11,638,000
Current maturities	1,467,000
Long-term capital lease obligation	10,171,000
Future minimum operating lease payments
2015	34,316,000
2016	27,196,000
2017	19,635,000
2018	15,630,000
2019	11,595,000
Subsequent to 2019	25,193,000
Total minimum lease payments	133,565,000
Rental expense for all operating leases
Rental expense for all operating leases	39,800,000	45,000,000	42,900,000
Rental income on subleases of equipment	700,000	600,000	600,000
Assets recorded under capital leases
Plant and equipment	4,807,000	14,509,000
Less accumulated depreciation	1,927,000	1,650,000
Assets recorded under capital leases	2,880,000	12,859,000
Capital lease obligations with lease agreements to acquire plant and equipment		2,200,000	9,300,000
Contract Termination | KC
Restructuring Cost and Reserve [Line Items]
Early lease termination penalties	$ 1,200,000