Impact of Recent Accounting Standards Not Yet Adopted Impact of Recent Accounting Standards Not Yet Adopted (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Mar. 31, 2017
Available-for-sale, Gross Unrealized Losses		$ 1,737	$ 1,940
Other investments
Available-for-sale, Gross Unrealized Losses	[1]	$ 496	$ 496

[1] (1) Primarily comprised of an investment in a CRA fund with 95% of its underlying investments consisting of government and agency-backed securities.