Acquisition Activity - Assets Acquired and Liabilities Assumed (Details) - Sabadell United $ in Thousands	Sep. 30, 2017 USD ($)
Assets
Cash and cash equivalents	$ 318,650
Investment securities	964,123
Loans	4,026,240
Core deposit intangible	96,607
Deferred tax asset, net	38,922
Other assets	89,935
Total assets acquired	5,534,477
Liabilities
Deposit liabilities	4,383,049
Short-term borrowings	520,539
Other liabilities	42,514
Total liabilities assumed	$ 4,946,102