Business Segments, Concentration of Business, and Credit Risk and Significant Customers (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Mar. 31, 2013
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Total assets for reportable segments	$ 1,168,613	$ 1,064,204
Unallocated cash and cash equivalents	158,226	245,088	49,126	64,591
Consolidated total assets	1,168,613	1,064,204
Reportable segments
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Total assets for reportable segments	803,119	654,679
Consolidated total assets	803,119	654,679
Unallocated to Segments
Reconciliations of total assets from reportable segments to the condensed consolidated balance sheets
Unallocated cash and cash equivalents		245,088
Unallocated deferred tax assets	39,483	38,933
Other unallocated corporate assets	$ 167,785	$ 125,504