Business Segments - Reconciliation (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Cash and cash equivalents	$ 245,956	$ 225,143	$ 245,088	$ 237,125	$ 110,247
Unallocated deferred tax assets	20,636	29,083
Total assets	1,278,068	1,169,933
Reportable segments
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Total assets	762,783	698,174	$ 654,679	$ 801,796
Unallocated to Segments
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Other unallocated corporate assets	$ 248,693	$ 217,533