Description of Business and Basis of Presentation (Recently Issued Accounting Standards) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2019	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized indirect leasing costs	$ 778	$ 2,800
Right of use asset			$ 69,500
Lease liability			$ 59,815
Weighted average discount rate			4.50%	4.49%
Cumulative effect of change in accounting principle					$ 22,329
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle					22,329
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use asset				$ 56,300
Lease liability				$ 56,300
Accounting Standards Update 2017-05 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle					$ 22,300