Note 12 - Subsequent Event (Details Textual) - Subsequent Event [Member] - USD ($) $ in Millions	Jul. 30, 2015	Jul. 23, 2015
Common Class A [Member]
Stock Repurchase Program, Authorized Amount		$ 5.0
Purchase of Corporate Headquarters, Maintenance Facility, and Surrounding Property [Member]
Other Commitment	$ 36.5

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant