Newt Gingrich's tax returns aren't the flashiest or the most complicated, but the former House speaker pulled in quite a few dollars in 2010.

Gingrich and his wife, Callista, made an adjusted gross income of $3,142,066 in 2010-most of it from one of Gingrich's companies, Gingrich Holdings, Inc., headquartered on K Street in downtown Washington, D.C.

Gingrich's campaign released his 2010 returns during Thursday night's debate in South Carolina, after the candidate repeatedly called on Mitt Romney to release his 2010 returns during the latest leg of the GOP campaign.

During the debate, Romney said he would release multiple years of tax returns. Until then, he had pledged to release his 2011 returns when they've been prepared in April. Romney recently said he paid an effective tax rate of about 15 percent in 2010, as capital gains accounted for most of his income.

Some highlights:

• Gingrich paid $19,800 in alimony in 2010
• The couple paid an effective tax rate of 31.5 percent, a total of $989,945 in taxes paid
• Gingrich drew $76,200 from the federal government, listed as income from the Office of Personnel Management
• Of their total income, the Gingriches made $2,478,539 from the corporation Gingrich Holdings
• The Gingriches made $191,827 from Gingrich Productions, Inc., a production company Callista Gingrich heads
• They made $60,868 in capital gains
• The Gingriches also reported losses on some investment portfolios, including $25,357 in capital-gains losses on long-term holdings
• They gave $9,540 to their church, the Basilica of the National Shrine, but Callista Gingrich also drew $5,918 in income from the church for singing in its choir
• The couple paid household help $14,774 in 2010
• Total charity giving added up to $81,133
• Gingrich has a bit of overseas holdings, too: he reported $1,681 in foreign qualified dividends
• The Gingriches own a house in Wisconsin worth nearly $78,000 but lost about $6,000 in depreciated value