Description of Business and Basis of Presentation (Recently Issued Accounting Standards) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
VIE, total assets	$ 92,000
Capitalized indirect leasing costs				$ 1,200
Weighted average discount rate	4.50%	4.49%
Right of use asset	$ 68,100
Lease liability	$ 58,115		$ 58,128
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