7. Retirement Benefit Plans

The Company sponsors various retirement benefit plans including qualified and nonqualified defined benefit pension plans for its employees. The components of net periodic pension expense are as follows (in thousands):

	Three Months Ended December 31,				Six Months Ended December 31,
	2012		2013		2012		2013
Service cost	$	306	$	309	$	584	$	602
Amortization of prior service cost	230		202		460		404
Net periodic pension expense	$	536	$	511	$	1,044	$	1,006

For the three months ended December 31, 2012 and 2013, the Company made contributions of $0.1 million and $0.8 million, respectively, to these defined benefit plans. For the six months ended December 31, 2012 and 2013, the Company made contributions of $0.1 million and $0.9 million, respectively, to these defined benefit plans.

In addition, the Company maintains various defined contribution plans. For the three months ended December 31, 2012 and 2013, the Company made contributions of $0.8 and $1.0 million, respectively, to these defined contribution plans. For the six months ended December 31, 2012 and 2013, the Company made contributions of $1.8 million and $2.0 million, respectively, to these defined contribution plans.