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Summary of Significant Accounting Policies (Tables) | 12 Months Ended
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Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract] |
Reconciliation Of Net Income Attributable To Common Stockholders To Estimated Taxable Income |
| (Unaudited and in thousands) | Year Ended December 31, |  |
|  |  | 2015 |  | 2014 |  | 2013 |  |
| Net income | $ | 76,907 |  | $ | 67,925 |  | $ | 56,915 |  |
| Straight-line rent adjustments |  | (1,418) |  |  | (2,538) |  |  | (3,707) |  |
| Depreciation and amortization timing differences |  | 2,477 |  |  | 2,283 |  |  | 2,134 |  |
| Reversal of liability for income taxes |  | - |  |  | (420) |  |  | (206) |  |
| Other |  | 751 |  |  | 765 |  |  | (2,186) |  |
| Estimated taxable income | $ | 78,717 |  | $ | 68,015 |  | $ | 52,950 |  |

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