Acquisition (Details) - USD ($)			12 Months Ended
	Jan. 01, 2015	Aug. 29, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Acquisition payment			$ 0	$ 0	$ 28,356,000
Decrease in contingent consideration			209,000	17,600,000	0
J.P. Morgan Retirement Plan Services
Business Acquisition [Line Items]
Acquisition payment		$ 59,776,000
Acquisition costs					2,859,000
Maximum potential earn out payment		$ 50,000,000
Months to make additional earn out payment		24 months
Earn out payment to acquiree			14,400,000
Decrease in contingent consideration			(209,000)	(17,600,000)	$ 0
Contingent consideration liability			$ 0	$ 14,609,000
Putnam Retirement Business Services
Business Acquisition [Line Items]
Cash paid	$ 4,114,000
Other assets assumed	11,501,000
Other liabilities assumed	7,717,000
Dividends	$ 330,000