Operating Leases (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Other information related to leases [Abstract]
Operating lease cost		$ 2,007	$ 1,954	$ 5,828	$ 5,794
Variable lease cost		497	492	1,472	1,546
Total Lease costs		$ 2,504	2,446	7,300	7,340
Cash paid for amounts included in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases				5,824
Right-of-use assets obtained in exchange for lease obligations:				$ 54,038
Weighted average remaining lease term		9 years 4 months 24 days		9 years 4 months 24 days
Weighted average discount rate		3.30%		3.30%
Future minimum lease payments under non-cancellable leases [Abstract]
2019	[1]	$ 1,967		$ 1,967
2020		7,820		7,820
2021		7,818		7,818
2022		7,300		7,300
2023		6,978		6,978
Thereafter		32,600		32,600
Total lease payments		64,483		64,483
Less: Interest		9,752		9,752
Present value of lease liabilities		$ 54,731		$ 54,731		$ 0
Minimum annual lease payments under terms of leases [Abstract]
2018	[2]		1,940		1,940
2019			7,799		7,799
2020			7,622		7,622
2021			7,555		7,555
2022			7,048		7,048
Thereafter			39,395		39,395
Total lease payments			$ 71,359		$ 71,359
Minimum [Member]
Leases, operating [Abstract]
Operating lease expiration term		2 months		2 months
Maximum [Member]
Leases, operating [Abstract]
Operating lease expiration term		25 years		25 years

[1] Excluding the nine months ended September 30, 2019.

[2] Excluding the nine months ended September 30, 2018.