Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Non-Voting Time-Vested Restricted Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of activity for non-voting time-vested restricted stock

	Share Units			Weighted Average Grant-Date Fair Value			Remaining Average Contractual Life (in years)		Aggregate Value (in thousands)
Outstanding at January 1, 2012		179,483		$	19.48			1.38	$	3,496
Granted		43,854			23.71
Forfeited		—			—
Vested and released to participants		(163,364	)		(19.36	)
Outstanding at December 31, 2012		59,973		$	22.89			1.83	$	1,373

Non-Voting Performance Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of activity for non-voting time-vested restricted stock

	Share Units		Weighted Average Grant-Date Fair Value		Remaining Average Contractual Life (in years)		Aggregate Value (in thousands)
Outstanding at January 1, 2012		—	$	—		—	$	—
Granted		152,044		23.11
Forfeited		—		—
Vested and released to participants		—		—
Outstanding at December 31, 2012		152,044	$	23.11		2.20	$	3,514