Credit Agreement (Details) (USD $)	6 Months Ended
Credit Agreement (Details) (USD $)	Jun. 30, 2013	Aug. 06, 2013
Credit Agreement [Abstract]
Debt Disclosure	Credit Agreement On February 11, 2013, the Company entered into a Credit Agreement (the "Credit Agreement") with U.S. Bank National Association (the "Lender"). The Credit Agreement provides for a $35.0 million (the "Credit Limit") unsecured, revolving credit facility. The Credit Agreement terminates on February 11, 2014 (the "Line Termination Date"). Under the terms and conditions of the Credit Agreement, the Company may borrow from the Lender until the Line Termination Date, with the aggregate principal amounts outstanding at any one time not to exceed the Credit Limit. As of the filing date of this Quarterly Report on Form 10-Q, the Company is in compliance with the covenants of the Credit Agreement and the Company does not have any amounts outstanding under the Credit Agreement.
Line of Credit Facility, Maximum Borrowing Capacity	$ 35,000,000
Line of Credit Facility, Amount Outstanding		$ 0

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References+ Details