Note 10 - Leasing Activities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases, Rent Expense	$ 182,040,000	$ 176,891,000	$ 152,967,000
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals	75,200,000
Land and Building [Member]
Operating Leases, Rent Expense	10,300,000	11,800,000	12,800,000
Vehicle Leases as Lessee 1 [Member]
Guaranteed Residual Value Under Operating Lease Arrangements	500,000
Guaranteed Residual Value Under Capital Lease Arrangements	34,000,000
Operating Leases, Rent Expense	1,300,000	2,400,000	4,100,000
Vehicle Leases as Lessor [Member]
Operating Leases, Income Statement, Minimum Lease Revenue	182,100,000	175,000,000	154,800,000
Operating Leases, Income Statement, Contingent Revenue	27,800,000	27,400,000	$ 24,500,000
Property Subject to or Available for Operating Lease, Net	570,100,000	592,000,000
Property Subject to or Available for Operating Lease, Accumulated Depreciation	262,600,000	$ 233,800,000
Minimum [Member] | Land and Building [Member]
Monthly Rental Payment Operating Lease	$ 275
Minimum [Member] | Vehicle Leases as Lessee 1 [Member]
Lease Term	1 year
Minimum [Member] | Vehicle Leases as Lessor [Member]
Lease Term	1 year
Maximum [Member] | Land and Building [Member]
Monthly Rental Payment Operating Lease	$ 46,479
Maximum [Member] | Vehicle Leases as Lessee 1 [Member]
Lease Term	10 years
Maximum [Member] | Vehicle Leases as Lessor [Member]
Lease Term	10 years