Deposits - Summary of Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Weighted Average Rate
NOW (as a percent)	0.06%	0.06%
Money market (as a percent)	0.26%	0.26%
Savings (as a percent)	0.05%	0.05%
Total core deposits (as a percent)	0.12%	0.12%
Certificates of deposit (as a percent)	1.01%	1.16%
Total deposits (as a percent)	0.28%	0.35%
Balance
NOW	$ 1,466,751	$ 1,415,430
Non-interest bearing NOW and demand deposit	1,054,343	998,393
Money market	2,706,895	2,560,204
Savings	2,048,202	2,137,818
Total core deposits	7,276,191	7,111,845
Certificates of deposit	1,600,864	1,994,182
Total deposits	$ 8,877,055	$ 9,106,027
Percent of Total
NOW (as a percent)	16.52%	15.54%
Non-interest bearing NOW and demand deposit (as a percent)	11.88%	10.96%
Money market (as a percent)	30.50%	28.12%
Savings (as a percent)	23.07%	23.48%
Total core deposits (as a percent)	81.97%	78.10%
Certificates of deposit (as a percent)	18.03%	21.90%
Total deposits (as a percent)	100.00%	100.00%