Loans - Outstanding Principal and Carrying Amount of Acquired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Outstanding principal balance and the carrying amount of loan acquired [Abstract]
Outstanding principal balance	$ 482,640	$ 63,619
Carrying amount	464,419	58,886
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Outstanding principal balance	62,006	24,500
Carrying amount	$ 51,297	$ 20,611