|
Investments (Fair Value Information) (Details) (USD $)
In Thousands, unless otherwise specified
|
Dec. 31, 2014
|
Dec. 31, 2013
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
$ 122,537 |
$ 106,963 |
| Investments |
123,608 |
106,963 |
| Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Investments |
1,071 |
0 |
| Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Investments |
122,537 |
106,963 |
| Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Investments |
0 |
0 |
| Mutual funds/Demand notes |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading Securities |
1,071 |
|
| Available-for-sale securities |
|
719 |
| Mutual funds/Demand notes | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading Securities |
1,071 |
0 |
| Mutual funds/Demand notes | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading Securities |
0 |
|
| Available-for-sale securities |
|
719 |
| Mutual funds/Demand notes | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading Securities |
0 |
|
| Available-for-sale securities |
|
0 |
| Corporate Notes and Bonds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
62,550 |
16,244 |
| Corporate Notes and Bonds | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
0 |
0 |
| Corporate Notes and Bonds | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
62,550 |
16,244 |
| Corporate Notes and Bonds | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
0 |
0 |
| U.S. government and agency securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
34,987 |
|
| U.S. government and agency securities | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
0 |
|
| U.S. government and agency securities | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
34,987 |
|
| U.S. government and agency securities | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
0 |
|
| Certificates of Deposit |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
25,000 |
90,000 |
| Certificates of Deposit | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
0 |
0 |
| Certificates of Deposit | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
25,000 |
90,000 |
| Certificates of Deposit | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Available-for-sale securities |
$ 0 |
$ 0 |