Leases (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended			12 Months Ended
		Jun. 30, 2019		Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018	Dec. 31, 2018	Jan. 01, 2019
Operating lease right-of-use assets		$ 28,174			$ 28,174			$ 0	$ 28,900
Operating lease liabilities		$ 30,210	[1]		$ 30,210	[1]		$ 0	$ 30,900
Operating lease weighted average discount rate		3.66%			3.66%
Operating leases, weighted average lease term		14 years 2 months 12 days			14 years 2 months 12 days
Operating lease rent expense	[2]	$ 940		$ 938	$ 1,879		$ 1,900
Options to extend reasonably certain of being exercised					4,200
Short-term operating lease liabilities		$ 2,500			$ 2,500
Minimum [Member]
Lease Expiration Period					3 months			5 months
Operating lease renewal term		1 year			1 year
Lease Expiration Period, Renewal Option								1 year
Maximum [Member]
Lease Expiration Period					22 years			22 years
Operating lease renewal term		5 years			5 years
Lease Expiration Period, Renewal Option								5 years

[1] Includes short-term operating lease liabilities of $2.5 million.

[2] Included in net occupancy expenses in the Unaudited Consolidated Income Statement.