Deposit Accounts Deposit accounts and weighted average interest rates (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Transaction accounts
Noninterest-bearing checking	$ 711,771	$ 456,754
Interest-bearing checking	134,999	131,635
Money market	743,871	526,256
Savings	83,507	74,508
Total transaction accounts	1,674,148	1,189,153
Certificates of deposit accounts
Less than 100,000	126,704	123,862
$100,000 through $250,000	166,397	163,819
Greater than $250,000	227,874	153,992
Total certificates of deposit accounts	520,975	441,673
Total deposits	$ 2,195,123	$ 1,630,826
Transaction accounts
Noninterest-bearing checking (as a percent)	0.00%	0.00%
Interest-bearing checking (as a percent)	0.11%	0.11%
Money market (as a percent)	0.35%	0.32%
Savings (as a percent)	0.15%	0.14%
Total transaction accounts (as a percent)	0.17%	0.16%
Certificates of deposit accounts
Less than $100,000 (as a percent)	0.79%	0.91%
$100,000 through $250,000 (as a percent)	0.91%	1.00%
Greater than $250,000 (as a percent)	0.72%	0.76%
Total certificates of deposit accounts (as a percent)	0.80%	0.89%
Total deposits (as a percent)	0.32%	0.36%