Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Item Effected
Retained earnings	$ 398,980	$ 339,959
Assets	6,293,745	5,887,284
Liabilities	5,530,155	$ 5,168,747
Accounting Standards Update 2017-08
Item Effected
Retained earnings	300
Accounting Standards Update 2016-02
Item Effected
Assets	9,970
Liabilities	10,750
Accounting Standards Update 2018-02
Item Effected
Reclassification of tax effects related to the Tax Cuts and Jobs Act	$ 720